Question for the "Normals"

How many people have to have a weird habit in common before it is no longer a weird habit?

For example, in the people I have talked to about this, more people than not prefer to sleep with no limbs dangling over the edge of the bed, in case something "gets them." (it's not always expressed about the WHY, but it's pretty obvious to me that if you aren't comfortable sleeping with pieces of you sticking out into the air, in the dark, it's because you think something might happen to them.) Does this majority preference mean that it is NORMAL to be afraid of a monster under the bed?

I was discussing different personal quirks with some people today and a couple of us separately mentioned that we know we probably do a bunch of things that are weird, but because they are "normal" to *us,* how are we suppose to know that they are weird?

And when does quirkiness cross the line into a disorder? Like, does it have to be disruptive to your life and bothersome to you personally before it's considered obsessive-compulsive? What if you LIKE being OCD? Is it still a "disorder?"

Who gets to make these decisions? And how do I get on that panel? mk