Lyric discussion by Loial73 

Cover art for Crazy lyrics by Barenaked Ladies

I think this song is saying "We're all crazy, different, and quirky to some degree, that just part of who we are and of being human." The speaker is "crazy" but so is the listener and it's nothing clinical (I'm not a manic depressive, paranoid or schizophrenic so I don't need your advice.) so it's something completely normal and natural. It's saying that this kind of crazy is just being different from others and that's completely fine.