Sometime you just need to act

Why do we always have to be sure of something before we do it? 

Perhaps the most predictable trait that individuals have is the need to understand everything, before acting on it.

Yet then, you put a bunch of individuals in a group and they don't have to understand things anymore. They tend to just act. 

Maybe it's the whole, "I'm not alone" mindset? Or maybe it is something more? Something on a deeper level that needs to be a member of a group. That part of humans that, for some reason, needs to belong. 

It is an interesting quark of human nature.