Most of my friends were ones I met in school or at university, so they're a similar age to me (21-22ish). There are a few outliers, however. My youngest friends are a pair of sisters who live in my old street. They're currently 18 and 19 years old, and I first met them about 10 years ago when they were playing in their garden. My oldest friends are about 25, and I met them at law school; I'm one of the younger people there, so most of my friends from there are older than me. I know some 30+ year olds, but I'm not sure I'd consider them 'friends'. Of these friends, I believe the oldest is 25, but I could be wrong!