In a comic universe that focuses on the inevitability of human corruption, Nightwing is a beacon of hope and goodness. More than just the inspiration for the Batman slapping Robin meme, Dick Grayson has been established as one of DC's best heroes. A non-powered human who regularly takes down superhuman foes, Nightwing also continues to fight against the corruption rampant in everyday society.
In Nightwing #78, Dick receives a letter from the late Alfred Pennyworth telling him, "I believe you can be one of the greatest forces for good this world has ever seen." Nightwing has a lightness in him that heroes like Batman never had. That's not to say he hasn't been through the same darkness as his mentor. Nightwing's writers have put him through a long list of messed things. Being put in danger as a child vigilante doesn't even make the top 10. Emerging from each of these situations with his hope intact makes him stronger than any other hero.
Watched His Parents Die
When his character was first created, Dick Grayson was 9 when he watched his acrobat parents plunge to their deaths. While more recent comics state Dick was a young teen when his parents died, it was a traumatizing experience no matter his age.
Nightwing spent most of his life believing his parents were meaninglessly murdered just by being in the wrong place at the wrong time. In the most recent Nightwing issues, writers Tom Taylor and Bruno Redondo, attempt to make his parent's death more meaningful. It doesn't change that watching them die, birthed in Dick the drive to find their killer, which set him on the path toward who he is today.
Temporarily Fired By Batman
In Robin: Year One, Dick Grayson was asked to stay behind while Batman takes on Two-Face. Being a child and stubborn, he disobeyed and ended up getting captured. Two-Face kills a captive and beats Dick almost to death in front of Bruce. Instead of conveying to Robin how worried he was, Bruce blames everything on his boy sidekick and fires him.
For Dick, who was still dealing with the murder of his parents, being fired without a proper explanation reinforces his already nascent abandonment issues. He has learned that all mishaps in the field are his fault and his place with his guardian not secure.
Kicked Out Of His Home
Continuing the theme of Batman being emotionally inept, Bruce would later fire Dick from his role as Robin a second time. Depending on what comic timeline is referenced, Bruce fired Dick the second time whether for spending more time with his Titans team than with Batman or for being shot by the Joker.
Either one is emotionally scarring as the man Dick sees as a father took away part of his identity. Dick was only a teenager, without a family or a home. His only other support system was the Titans, a team of other teen heroes dealing with their own villains and issues. None of this was a good setup for emotional or mental stability. Yet Dick emerges as Nightwing and pushes forward despite it all.
Batman Didn't Tell Him Jason Died
After Dick left Wayne manor, Batman gave the name Robin to another boy. Struggling with his past hurts and an extremely poor relationship with Bruce, Dick found it hard to get to know Jason Todd, the new Robin. Despite this, he was still upset to learn of Jason's death. Bruce once again was unable to handle his own emotions and didn't even tell Dick that Jason had died. Dick learned about it second-hand after the funeral.
Bruce's actions nearly broke his relationship with Dick permanently. It was only Tim Drake's eventual intervention that brought them back together. Even after that, their interactions were strained. The more recent Nightwing issues show that Dick has learned not to be like Bruce, thanks to all the emotional trauma in his life for which Batman is responsible.
Never Officially Adopted
Dick Grayson was the first Boy Wonder, the first child taken in by Bruce Wayne, but not the first to be adopted. Dick was a ward of Bruce's, which kept him out of the foster system but didn't make him officially Bruce's son. Bruce adopted both Jason Todd and Tim Drake long before offering the formality of "adopting" an adult Dick Grayson.
Dick came to believe that he wasn't as important as the other members of Batman's family. He sacrificed himself and was reckless, believing he wasn't worth as much as the others. As Nightwing, he struggled to learn to ask for help, feeling like he was letting Bruce down if he did.
The Blockbuster and Tarantula Storyline
During his early years protecting Bludhaven, Nightwing became a permanent thorn in the side of the villain Blockbuster. Determined to destroy Nightwing, Blockbuster figured out Dick's identity and threatened everyone he ever came in contact with. The mob boss even blew up Nightwing's apartment building and burned down Haley's Circus, Dick's old home. At the time, Dick was training a vigilante called Tarantula. She decided to help Nightwing by killing Blockbuster.
Nightwing was so upset over not stopping Tarantula from committing the murder that he went into shock. Taking advantage, Tarantula forced herself on Dick without his consent. Unfortunately, this is not the only time someone has disregarded Dick's consent and bodily autonomy.
Crime Syndicate and Spyral
At one point, Nightwing was kidnapped by the Crime Syndicate, revealed to the world, and strapped to a bomb that was linked to his heartbeat. The timer would stop only when his heart did. Lex Luthor ensured he died temporarily, and although Dick was brought back, Batman had already told everyone that Dick was dead and even had a funeral for him. At that point, Nightwing's mentor literally beat him into submission so he'd join Spyral as an undercover agent.
Instead of acting with compassion for his son's near-death experience, Bruce reinforced to Dick that the mission came first, even before his own life. Fortunately, Superman and Alfred Pennyworth have always been there for Dick to balance out Bruce's darkness.
Shot in the Head
In another brush with death, Dick was shot in the head by KGBeast. It was a traumatic cliffhanger for fans, with a heartbreaking ending. Dick survived the shot, but his memories did not. He left behind the vigilante life as Nightwing, pulling away from his family and friends.
It's a long time before Dick returns as Nightwing. Before that, he had a stint as a taxi driver named Ric who drank and fought for money. Beyond losing his identity, the worst part was that he lost his fiancee, Barbara. A few issues before the shooting, they finally agreed to get married. Getting shot in the head changed who Dick was, ruining his relationship with Babs.
Forced to Watch Bludhaven Burn
During the Infinite Crisis, the Secret Society of Supervillains sought vengeance against Nightwing by destroying Bludhaven, the city he swore to protect. Chemo, a semi-sentient vat of deadly radioactive chemicals, was dropped on the city, leaving destruction and chaos in its wake. The city was put under quarantine and all heroes were forced to leave, the fallout of which eventually destroyed the rest of the city.
Nightwing was forced to watch the destruction of the place he had called home since leaving Batman. Because of the conditioning he suffered at the hands of Bruce, Dick took the city's destruction as one of his greatest failures even though the tragedy was not his fault.
Became Batman
One of the things that Nightwing never wanted to become was Batman. Taking on the cowl would drain his spark, dragging him into the darkness in which Bruce existed. Batman made hard choices that lacked compassion, and never fully trusted anyone but himself. Dick wasn't built the same way.
During the time Bruce was thought to be dead, Dick, in his usual self-sacrificing fashion, finally became Batman. He strove to keep his brothers from fighting over the cowl and to keep Gotham safe. Even while stepping in to fill a role he never wanted, Dick stayed true to himself enough to be the father to Damian Wayne that Bruce never was for him.