Well, what's the alternative? Sit and stare into space, looking all deep and meaningful, while pondering the universe as a single tear rolls down your cheek?
People that 'get on with it' aren't any less intelligent. They still think about 'deep' things. They've just realised that they're not special, they're not thinking incredible new thoughts that nobody has had before, they're not going to find all the answers. And if they waste all their time thinking that they are something that they're not, then life will pass them by and they'll end up feeling just like you do.