In the first season, Topanga was this eco-friendly/hippie feminist character, who desired to become a lawyer. In a nutshell, she had much more personality. But once she became Cory's girlfriend, it became more focused on her looks and this narrative of them being destined to be together. For whatever the reasons, they decided to rewrite history with each other -- when Cory said she knew she was the one, the first day he saw her on the playground. Bare in mind that they couldn't even stand each other in Season 1.

But from there, it seemed like Topanga was really lowering her standards for Cory despite having so much going for her on paper. I mean, after her family moved away, she if I'm not mistaken came back to live with Cory and the Matthews. She also gave up Yale for him.

I agree that topanga was more interesting in the first season. much of that stemmed from her parents, who were also portrayed differently later on. however, she was always nice to Corry. he was the one who was somewhat mean to her for the most part.