idiosyncrasy
/ˌɪd.i.əʊˈsɪŋ.kɹə.si/noun
A habit or way of thinking that is particular to one person.
Example sentence
- “Wearing gloves indoors was one of his little idiosyncrasies.”
Spelled with 'crasy' at the end, not 'cracy' as in 'democracy'. A neutral word: the quirks it names are odd, not necessarily bad.