The Big Bang Theory started out being about a group of male nerds coming into with a hot but not very bright waitress, and the contrast between the two provided much of the comedy for the show. But soon the series found it could not keep making the same jokes about the same group of people.
So Amy and Bernadette were added to the mix and were successful in expanding the reach and range of the show with a new perspective on what it means to be women in the scientific field who often struggle with the same issues with social interaction that the male nerds did. And Amy's journey on the show provides many life lessons to viewers.
Your Past Doesn't Define You
It's arguable who had a worse childhood between Amy and Sheldon. but a lifetime of repression and not fitting in did a real number on both their psyches. In Amy, we see the effects of her past in the way she has trouble making friends, does not understand basic social interactions and her repressed attitude towards her own sexuality.
But despite the things in her own mind holding Amy back from becoming fully self-actualized, she was able to break through her conditioning and become a successful professional with many close friends and a loving boyfriend.
Arrogance Doesn't Get You Friends
When we first met Amy, she was basically a more insufferable version of Sheldon, convinced of her own superiority thanks to her brain and dismissive of all of Sheldon's friends as beneath her for not being as smart as her and Sheldon. This Amy was roundly disliked by everyone.
It was only later when she became more humble and saw the others as her equals, and even her betters in some regards, that she was able to befriend them.
Being Needy Is Off Putting
From being arrogant, Amy then did a 180-degree turn to become the neediest member of the group, which is saying something where this particular bunch was concerned. Especially with regards to Penny, Amy was so desperate to have the pretty, popular blonde like her that she became a doormat, and would constantly compliment Penny about her body.
Instead of becoming flattered, Penny found this sort of attention distinctly discomforting. It was only after Amy calmed down a bit and started behaving more normally that the friendship between the two really took off.
Giving Gifts Won't Buy Affection
Amy once spent several thousand dollars on commissioning a portrait of herself and Penny that she then gifted to Penny. The gift was not well-received, and Amy had to take it back to her apartment in mortification until Penny finally felt guilty enough to beg for it back.
This entire incident did nothing to make Penny like Amy more, and all that happened was Amy blew her own money on an unwanted painting. Once again, Amy sought to find a shortcut to becoming Penny's friend instead of putting in the years of effort in being there for each other that results in genuine friendships, and the ruse did not work.
Life Is Not Like High School
When Amy became a part of the group, she was excited to be a part of the 'It' crowd, something that she had never been able to do in high school. She got so caught up in living that fantasy that she started back-biting, complaining about Penny to Bernadette and vice-versa. The whole incident showed Amy in a very poor light, and her relationship with both suffered as a result.
What finally worked for Amy was realizing she was not in high school anymore, and the friendships during adulthood rely on maturity and rather than shallow bitching about others and surface appearances of friendliness.
Own Your Quirks
Like most other nerd characters on the show, Amy has her own strange quirks, like her fondness for harps, her habit of saying the wrong thing at the wrong time, and her proclivity for babbling scientific jargon at people who are not interested.
In the beginning, Amy was quite conscious of these quirks and even tried to curb them in order to fit in better. By the end, however, she was able to understand the fact that her strange habits made her unique, and were a big part of what made Sheldon love her.
Open Yourself Up To Emotions
Amy and Sheldon have a harder time than the others to open themselves up emotionally. This was a result of a lifetime of repression for both in order to fit into a society that punished them for being intelligent and rigid in their rules.
A big part of the journey for both characters has been them learning to be open about their feelings. In helping Sheldon become more emotionally honest, Amy has herself understood the importance of expressing her feelings.
Know When To End A Relationship
Amy worked long and hard to make her relationship with Sheldon work. She put up with his obnoxious qualities and was patient with his reluctance to move the relationship forward past a certain point. But the more she gave of herself, the less it seemed Sheldon appreciated her sacrifices.
Finally, Amy realized that as much as she loved Sheldon, he was not ready to commit to her, and forced herself to break up with him. This was the kick in the pants that Sheldon needed to analyze his own feelings and realize how much he loved Amy.
Stand Up For Yourself
The biggest source of Amy's repression has been her domineering mother, who conditioned her daughter to be suspicious of men, her own body, and relationships in general.
Amy's mother was also firmly against Amy marrying Sheldon, and even interrupted the wedding to voice her objections. With the help of Penny, Amy was finally able to stand up to her mother's bullying ways and go through with the wedding.
Brains Over Beauty
Penny and Bernadette are often complimented for their looks, while Amy is frequently slighted for hers. A lack of physical beauty has been a large part of Amy's low sense of self-worth.
Yet, by the end of the show, Amy, through her own efforts, has arguably the most successful life of all the girls. She is at the top of her field, a Nobel prize winner, and married to the love of her life. Amy proved you don't need to have supermodel looks in order to have a happy, fulfilling life.