It's different for kids though isn't it ? They don't have much else to think about and they spend huge amounts of time together, same with students - that's why deep friendships are formed in the childhood years - shared experiences, same phase of life etc etc.
As an adult there is so much else going on - different backgrounds, different attitudes, partners to consider, work, children etc we just don't ahev the time to invest which is why I think it takes longer.
I think she's right - I really do.
I thought my antenatal friends were real friends, but they weren't, we were all too different, we were at same life stage, had common interset (babies) but as they grew up and went to different nurseries, some of us went back to work, some disapproved, the group fragmented. We kept meeting for a while but all we talked about was the children - it was dull, there was nothing there and it all broke up. I don't even have their addresses now and dd is only 6.
Read a good article once - different friends for different phases or something. Some are good for a reason - ie. support at work, some are transitional - like antenatal groyup, and some are friends for lief.