can you be fast friends with those who are very different from you?

had this thought a long time ago but since i verbalized this thought to aida tonight, i figured i would record here for all posterity

look at the cast of F.R.I.E.N.D.S. diversity makes for engaging TV but is such diversity realistic in real life contexts? or in Singapore, which i think its citizens are stratified on the basis of educational qualifications, income level, family background, ownership of cars etc