Quoting DifferentDay:" What quirks or OCD tendencies do you have? I have not been diagnosed but I have looked up my "symptoms" ... [snip!] ... doors and making sure they're locked multiple times a day/night. ....There's lots more I just can't think of any right now."
YOU ARE WEIRD LIKE ME!
I turn letters into numbers and reduce words to single digits.
Such as, if "ABC" was a word, it would be 1 plus 2 plus 3. Put together it's 6. Nothing to reduce. If I wrote " ABDG" it would be 1 plus 2 plus 4 plus 7. Add together it's 14. Still have to reduce. 4 plus 1 is 5. So I make letters into words and words into numbers and reduce them to a single digit.
I count my steps.
I crack my knuckles obsessively.