User blog comment:AlexCat/Have you ever woundered how... P+F curiositys/@comment-4672566-20111224025617

Actually, I do happen to have a theory about this... I think that Ferb is a very individualized person. I think that he's quiet, not because he doesn't like to talk, but because he doesn't really need to. Ferb is very intelligent and can understand things easily, explanation is not needed when it comes to him. Phineas however can be at times rather... dense. He sometimes doesn't notice things when they're directly in front of him. He needs things to be explained or he just won't get it. Because of this Phineas actually forces Ferb to talk. Once Phineas got Ferb to talk, Ferb just opened up to Phineas. Notice how it's always Phineas who mentions Ferb being a chatterbox. Ferb probably trusts Phineas more than anyone else in the series, and Phineas is just a really nice guy. There's also the fact that Phineas and Ferb have lived under the same roof for over half of their lives (likely) I don't care who you are, but if I have to share my house, television, computer, bathroom, clothes, food, and whatever else you can think of, for seven years, I'm going to get to know you fairly well. Actually, y'know I have some friends who trust me more than their own family, and I don't live with them... and even if they're quiet in public, I can get them talking for hours. And when you get people to talk like that, you can learn a lot. I imagine that Phineas has the same effect on some people... particularly Ferb. Over time, they truly did become brothers. There's also one big theory I have. They compliment one another. If Phineas wasn't there for Ferb, Ferb would be isolated from everyone his age, he would have never opened up, and be even more silent than he already is. He would have a lot of potential building talent, however nothing to use it on since he wouldn't imagine up what to do and how to do it. Phineas on the other hand would have a lot of creative, big ideas, but no means to follow through with them. In other words, they need each other. They wouldn't be able to work by themselves. That a good explanation for you?