He may wish the galaxy to refer to him as Star Lord, but deep down he's just Peter Quill, a half-human swashbuckler who went from a rebellious scoundrel to the leader of the Guardians of the Galaxy. His story arc can be attributed to a series of character traits that helped define him as a reluctant, would-be superhero.
At heart a good guy with a mischievous side, Quill's path to superhero status required that he take the long way around to get there. Yet, he still sticks by the same character traits that made him the man he was, and helped open his mind to new possibilities when it came to family, friends, duty and honor.
He's A Romantic
Though he started off as a notorious intergalactic womanizer, Peter soon realized that he was more than capable of being a good old fashioned romantic. After all, he had a great head start, thanks to his mother's love and kindness, and the inspiration she bestowed on him.
By the time he met Gamora, his entire life had begun to change. She represented a new chapter for Peter, one that a lot of men go through when they decide to settle down, and devote themselves to one special girl. His love for Gamora was so strong that he would have moved the entire universe for her, which is why her death at the hands of Thanos was so traumatic for him.
He's Nostalgic
Peter Quill is time-locked firmly in 1970s and 1980s pop culture, and it's the vehicle that drives a lot of his ambition and inspiration. He prizes nothing more than his Sony Walkman, and a series of mix tapes created by his mother, featuring the absolute-best songs of the time period. This, despite the nonsensical aspects of Peter Quill's character being able to assemble a tape deck on board a starship, in the first place.
He also waxes nostalgic about 1980s movies, especially ones starring Kevin Bacon. For those who grew up in the 1980s, they knew exactly where Quill was coming from. The experience of growing up in that particular decade is something future generations simply cannot understand, no matter how passionately it is described to them.
He's Impulsive and Reckless
Though Peter does know his limitations, he's also quite prone to being impulsive and reckless, especially in battle. Some of his tactics and plans seem chaotically ingenious, especially when implemented, but they also cross a number of lines that any strategist would balk at.
Perhaps his worst act to date was attacking Thanos in a rage, following the news that he had sacrificed Gamora in order to acquire an Infinity Stone. In that heated moment, nothing mattered, and it ended up costing the universe.
He Has Problems With Authority
Raised a Ravager, it was obvious that Peter would have negative thoughts about law enforcement, and authority in general. Deep down, he's a rebellious high school kid who doesn't want to listen to anyone, and prefers to dance to the beat of his own drum. Naturally, this can be problematic at times.
Whether it's Tony Stark trying to take control of team leadership, or the forces of Xandar threatening to throw him in prison, Peter does not take kindly to any of it. He'll resist the entire time, and further cement his rebellious attitude.
He's Insecure
Peter is a very boisterous man, and part of that boils down to an inferiority complex. Everything he does is grandiose, loud, and over-the-top, on purpose. It's his way of showing the galaxy that he's cool, calm, and in control of everything. That's not the entire truth, however.
In reality, Peter is actually quite insecure, especially when it comes to showing his feelings. It takes a lot for him to feel comfortable enough to do it, though once he's crossed that threshold, he's remarkably open-hearted. The trials required to get there are another matter, however. He also dislikes when the spotlight is taken off of him, as demonstrated by his relationship with Thor in one of Peter Quill's most shameless moments.
He Is A Family Man
Though he usually fancies himself a lone wolf, Peter actually has a strong sense of family bonds. In fact, it was his bond with his deceased mother that allowed him to form such a close bond with his fellow Guardians, who he viewed as his real family. There was little he wouldn't do to protect them.
Of course, this family was as dysfunctional as they came, but to Peter, they were the anchors he needed to stay grounded, and give him purpose in life. When Gamora was lost during the Infinity War saga, a part of that family was torn violently from him, and he never fully recovered from it.
He's Very Creative
For such a wisecracking rebel, Peter was exceptionally talented when it came to crafting solutions to various problems. In fact, he could do so on the fly, with very little time to sit and formulate a strategy. When the chips were down, he could devise run-and-gun schemes based on the facts he had at the time. Better yet, he could adapt and change those plans in the middle of a battle.
It was Peter who managed to distract Ronan with an impromptu dance-off in one of Star-Lord's funniest himbo moments, to great effect. He also came up with the idea to trap Thanos and remove the Infinity Gauntlet from his arm. The scheme proved to be an enormous success, but it was undone by his own rage at the news that Thanos had sacrificed Gamora. Had he stuck with the plan, the snap would never have occurred.
He's Incredibly Sarcastic
Humor is often used by extremely extroverted people to hide inner pain, and Peter had enough of that to spare. He was forced to watch his mother die slowly of cancer, and afterwards, he was left without the most important person in his life. To compensate for the pain, and the lack of love he experienced afterwards, he became very sarcastic.
This was actually a beneficial tool a lot of the time, as it allowed him to get a leg up on his enemies, charm women, and help take his mind off his own negative feelings. However, it wasn't enough to fill the hole in his heart, which is where his fellow Guardians came in.
His Piloting Skills
Peter is an excellent pilot, and he demonstrated it multiple times throughout the MCU films. Part of this had something to do with his go-for-broke personality, and a willingness to push the envelope with crazy schemes and plans. Most of the time, they paid off, especially when the stakes were very high.
Quill first demonstrated his piloting skills to excellent effect in the first Guardians of the Galaxy film, when he disrupted Ronan's forces during the attack on Xandar. Having grown up with the Ravagers, it was practically in his blood by that point.
He Has Extreme Daddy Issues
It's safe to say that Peter doesn't have a good track record with father figures. His original dad was none other than the Celestial known as Ego, who was responsible not just for his birth, but the death of his mother. This caused the two to clash, with Ego being destroyed in the process.
Peter was taken in by the Ravager known as Yondu as a young boy, and raised by the pack. Their relationship was extremely volatile, though Yondu secretly loved the young Peter, and wanted to make sure he could take care of himself. Some fans hold unpopular opinions about Peter's relationship with Yondu, but he sacrificed himself to save Peter's life, which was especially traumatic for his adopted son.