Everything? Sex? Naw. I don't buy it. I think from adolescence
onwards, some people get 'stuck' in a repeating cycle of
attempting to recreate the intensity of the sensations one had
in the early onset of puberty, to relive the fantasyland
sensation and confusion and control and resolution...
...but no, I don't think everything leads to sex or comes from
sex.
If it's your hobby, by all means. But, it's not everybody's
hobby.