I'm starting to really feel this too. I am doing my Phd at the same uni I did my BA and MA at - but now I'm pretty much alone. The MA was great, the core group of us from the BA went on to do it together and it was just brilliant - we had a lot of fun - they have all left now, and I was saying to my supervisor the other day that although I'm in the same dept, going in and out of the same rooms that I have done for 4 years now, it feels totally different. There is no chance of bumping into somebody in the library or in the squares - nobody to text or email to chat to, nobody to meet up with for a moan, nobody to sound off on. We are quite a small dept - I think there are only about 15 or so active research students, all or which are at a different stage to me - I say that, there are 4 of us this year, but you wouldn't know it. They are people I didn't know, studying different things, and we all work from home, I don't even know who they are! I know a couple of second years but again, they are so rarely on campus, and I work from home that there hasn't been a chance to build up any friendships yet. Its all quite depressing actually. I'm a mum and so can't go and do anything else - I have to spend time with the children - it is just so so different from the last 4 years where there was always somebody to have a coffee and a chat with and to feel that you were normal lol. I find I'm leaning more and more on this forum and checking it regularly to see what's going on and to talk to people who really understand.