what is the single most revealing thing about any person that you can observe ?

the best way really to know a person would be to see what he does in his free time. people with mediocre ambitions tend to waste time in useless social conversations and socializing with other mediocres. the intellectuals howver invest this time on educational websites like Quora sharing and gainiing knowledge. discussing ides and getting involved in productive conversions which help the mind and thoughts to grow.

a relevant quote here would be this one by Eleanor Roosevelt;

" Small minds discuss people;
Average minds discuss events;
Great minds discuss ideas. "