Phineas And Ferb: Season 4, Episode 47

4 - 47: Act Your Age

It's been 10 years after the events of the present, and Phineas must decide what university to go to. After discovering that Isabella had a crush on him for years, Phineas must reach her before she leaves for college and express his true feelings for her. Meanwhile, Doofenshmirtz has a mid-life crisis.