Cuckoo's Nest

I feel like I've used this phrase about 300 times in the last month...

I was wondering though, what makes someone cuckoo? Is craziness a subjective thing?

What is the line that marks the switch from "cute quirk" to "annoying eccentricity"?
Does this line vary from person to person? If so, which person does the variety: the quirky person or the friend of the quirky person?

Maybe this doesn't make sense. Let's use a for instance: Let's say Jane has a habit of popping her gum...but you love Jane...so it doesn't bother you...Now, Judy also pops her gum...but since you have a difficult time with Judy, it drives you crazy. So you must be the variable...right?

Well, how about this...Jack belches loudly and a lot. He does so in front of his closest friends...for the most part, they don't seem to mind. He would never do this in front of his new girlfriend--so he is the variable...right?

Do you hide your crazy until you know someone truly loves you or do you let your crazy out and hope they adore you more for it?

Maybe this post is me putting my crazy out for the whole world to read?!

What crazy quirk do you reserve for best friends?