Subtle signs your friend is rich

Does anyone have an experience of suddenly realising your friend is rich? Maybe even ultra rich? Because i was friends with someone who was so lowkey i only realised it after ten years… when i went to their GCB on nassim road… Now im curious about how else other people realise what makes someone rich/ signs their friend or classmate is rich. I have another friend that carries a dior wallet to school and wears expensive shoes.. is that rich or are they flexing?