As a child I was obsessed with symmetry.
Things that were uneven on one side or the other bothered me. I hated that my little batmobile toy only had batman and that robins seat was empty. (eventually I figured out how to get the little encased batman figure out so both seats were empty).
If my hand itched and I scratched it (and I was thinking about it at the time) I would also scratch the other one so it would be even.
What finally broke me out of this was one of Fisher Prices ‘adventure people.’ Specifically one of the EMT helicopter pilots. Adventure People were an action figure that had one arm in a slightly different pose than the other, sort of pointing or pushing a button. This used to bother me, but one day I suddenly really liked it. And like a switch I began to appreciate asymmetry.