Are you kidding! That is still so young! I was 19 when I started Uni and there were so many 20/21/22 year olds. Until you asked a person's age I honestly wouldn't be able to tell between then 19-22 bracket. I'm living with one 22 year old now and the rest of us are 20. It makes no difference. After I'm planning to go travelling with a girl who I work with who will be 26 (and I will be 21), she looks about 19 and acts the same age as me. I literally think age makes no difference whatsoever so a certain extent!
Also, there are 3 people on my course over 35 and lots of 23,24 year old although the vast majority are 20.
Hope this helps