I kinda agree.
My first year was a bit lacklustre. My flatmates were cool, but they girls were the really popular sort who hung out with the football boys and the other 2 guys had loads in common so spent lots of time with people on their societies. I made friends in the lectures and practicals but didn't see most of them enough to call them 'real friends'.
I ended up staying in halls again for my second year, which so far, has turned out to be a great decision.
I'm really close with the guy and 2 girls in my flat (other 4 are international and don't really appear much) and we've got friendly with some people from the floor below. It's only been 4/5 weeks, but already we're talking about houses next year.
It does seem hit-or-miss to be honest how many friends you make based on flatmates and who you talk to in the first few weeks. Societies are also a good call for friends, because you know that you will regularly see them again and you already know you've got something in common!