Ep 17. Lisa the Simpson

In season 9 episode 17 of The Simpsons, titled "Lisa the Simpson," we see Lisa struggling with her identity as the only Simpson who seems to have inherited none of the family's innate talents or quirks. After taking an IQ test, Lisa is dismayed to learn that she is actually far less intelligent than she thought, and even dumber than her own brother Bart.

Feeling dejected, Lisa tries to find her place in the world by joining a group of fellow "average" students at school. However, when she discovers that their idea of fun involves vandalizing property and playing with dangerous chemicals, she realizes that she doesn't truly belong with them either.

In the midst of her existential crisis, Lisa discovers an old family journal that belonged to her ancestor Eliza Simpson. Reading through its pages, Lisa realizes that Eliza went through a similar struggle to find her purpose in life, but ultimately found meaning by dedicating herself to helping others.

Inspired by Eliza's story, Lisa sets out to do the same, using her knowledge and skills to help her community and make a difference in the world. Along the way, she discovers that intelligence isn't the only measure of worth, and that even those who don't fit in with the norm can find their place and make a difference.