User blog comment:StacyFan/More at2d news/@comment-2163002-20110613231606

Based off what the person who uploaded said about there being Phinebella moments in the movie, I believe that Phineas will find out about Isabella's crush on him and then forget about it by the end of the movie. Perhaps he finds out about it and then has his memory of the movie's events erased due to finding out Perry's secret?