Leonard Hofstadter is the sheepishly brilliant experimental physicist in The Big Bang Theory. For 12 seasons, Leonard has grown a lot in a multitude of ways, both physically and mentally. As a man who's self-conscious enough for the entire friend group, Leonard faced his fears to get what he wanted, even if it meant he failed. And without knowing it, he did the same thing with his style.

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As much as women like Priya and Dr. Stephanie Barnett tried to change Leonard, the only person that could change him for the better was himself. In order to grow and emerge with the times, Leonard had to dig deep and be brave, which is something the character doesn't get enough credit for. To see all the ways Leonard has slowly changed over the years, take a look below.

Scared In Season One

Sheldon and Leonard sitting side by side in the office on TBBT

The pilot episode of The Big Bang Theory did a great job of showing exactly who Leonard was at this time. He was nervous, he fidgeted a lot, and he questioned most of his own decisions. Leonard left the sperm bank with Sheldon in a tizzy and later became speechless when he had one look at his new neighbor Penny across the hall.

He had the bravery to invite her over for dinner but stumbled on the right words to say. While he did become braver as the series goes on, this was the start of Leonard's love affair for cargo jackets and hoodies underneath...

Trying His Best In Season Two

leonard in season two of tbbt

In the second season, Leonard is still that shy scientist but he's willingly trying to become an extravert to get the things he wants in life; which is commendable. Not only did he finally ask Penny out on a date but he started dating Leslie from work and later a woman (Stephanie) that his friend liked. It's obvious that Leonard was a tad desperate in his dating life but unlike his friends, Leonard was trying his best at being a go-getter.

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At this point in the season, Leonard's style is similar to season one but he does dress up now and then to impress the women he's trying to woo.

A Changed Man In Season Three

the group comes home from the arctic - the big bang theory

When Leonard and co. come back from the North Pole in "Electric Can Opener Fluctuation," Leonard is wearing a completely different look. His style has remained the same but it's what's on top that we can't stop looking at. His hair was the longest we've ever seen it and his beard was running wild! Luckily for Penny, this look didn't last long but it was enough of a draw to pull Penny into his arms.

After being apart for months, Penny realized distanced made the heart grow fonder and that she really liked Leonard. Knowing that Leonard had just caught the woman he's been in love with for years, he began acting a little too confidently. He was too overzealous and practically drove Penny away.

Longing For Love In Season Four

leonard in season four of the big bang theory

Leonard doesn't get enough credit in the fourth season. He may be shy and a tad dorky but he has the right amount of quirkiness to win over Raj's sister Priya. Unlike Penny, Priya had both brains and beauty. On paper, he and Priya would seem like the perfect match. They were both brilliant and determined and had far more in common than he and Penny.

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With Priya liking Leonard so much, it shows how much Leonard's game has changed since season one. He finally had the right delivery and charisma to land someone like Priya! As fans know, however, this relationship didn't last. Leonard was still longing after Penny and began to second-guess himself.

Too Cocky In Season Five

season five in tbbt with leonard

Fans were screaming at their TVs when Leonard was brazen enough to cheat on Priya with a woman he met at the comic book store. For a man who always wanted a beautiful girlfriend, he sabotaged himself the minute someone else was interested in him.

It was in this season we saw a major downward spiral in Leonard's personal life. For a man who almost had it all, he was eager to throw it all away for zero rewards.

Building Back Up In Season Six

The Bakersfield Expedition

When the sixth season rolled around, Leonard mended his broken heart and fell back into the arms of Penny. The two gave dating another chance but yet again, Penny thought the relationship was boring. The two had such a strong friendship that it made their personal relationship seem dull.

Not to mention Leonard was still trying to recover from his mess-ups in the past. After being too confident with Priya, he was back to square one when dating Penny for the second time. Especially after hearing that she wasn't vibing their new relationship. In terms of style, Leonard's season one style still remained but he knew how to get Penny's heart racing when he wanted to.

Leonard Puts It All On The Line In Season Seven

season seven of tbbt with leonard

Season seven was a big season for "Lenny." He finds out his serious girlfriend was legally married to her ex-boyfriend in "The Thanksgiving Decoupling," which practically broke them up. Leonard couldn't handle the fact that Penny would marry a guy like Zack on a whim but wouldn't even entertain marriage with him.

Over time, however, Leonard and Penny found their stride. Leonard's hair got a little longer, he and Penny became more open with each other, and they finally came to an understanding that they were end-game for one another. By the end of the season, Leonard's vulnerability was enough for Penny to agree to marry him.

Leonard's Brazenness Got The Best Of Him In Season Eight & Nine

SEASONS 8 AND NINE OF TBBT

Although Leonard got the girl of his dreams and everything he's ever wanted, he went back to his old ways and sabotaged the relationship. On the night of his wedding in Vegas with Penny, he told her that he cheated on her when he was away at sea.

Considering he spent years chasing Penny and trying to convince her that they were the right match, it was shocking to see him so spineless when tempted.  This mistake took some time to get over, especially for Penny. Physically, Leonard has never looked better. Aside from cheating on Penny, he seemed confident and relaxed in his skin.

Moving Forward In Seasons 10 & 11

LEONARD IN SEASONS 10 AND 11 OF TBBT

By the 10th and 11th season, Penny and Leonard are finally living together and spending time as a married couple. Penny has transformed herself and has a great job, something that never seemed possible in prior seasons. Likewise, Leonard started focusing more on work after everyone else was doing amazing things in their careers. He almost lost it all when a bad radio interview went viral but he eventually made it right for the sake of his job.

With a fresh start at work and finally living alone with Penny, he and Penny got married again in front of their friends and family. It's onward and upward for Leonard!

Leonard Came Into His Own By Season 12

LEONARD IN SEASON 12 OF TBBT

By the 12th and final season of The Big Bang Theory, Leonard has completely transformed. He's not the shy poorly dressed guy who wished for big things to come his way. He was now a husband with an aspiring career who's about to become a father. He has a chance to be the loving parent he never had and to fully immerse himself in his life with Penny.

He also had the experience of seeing his best friend and former roommate win a Nobel Prize, which could only lead to more windows of opportunity for his research. Leonard has come full circle in season 12 and fans were happy to watch him blossom.

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