What makes a Naturist a Naturist?

I'm trying to understand the mind of someone who likes and-or longs to walk about naked in public...Why? Is this down to their upbringing, were their parents naturists? Are naturists perverts, s? Are they obsessed with their own bodies..Are they vain...Do they find themselves so irrisistable that they want everyone else to see?...... From the mind of a Non naturist i can not for one minute contemplate their way of thinking.... I have a good body but if someone asked me to walk around naked i would say, no way!! theres no one getting to see my private parts without getting prior permission first...no freebies here sorry!