I'm in a similar situation as the OP. I worked for 7 years post undergrad and had saved some $. I've also always lived in same city as my grad sch and therefore didnt have to move into a shoe-box, unsafe apt near campus, as most of my cohort. I simply dont bring up my "extra" finances. We've gone on a couple of weekend outings and they were affordable places. I'll probably host a Thanksgiving dinner, not to rub it in their faces, but coz I know most of them are new in town and will probably not have an opportunity to get home for the holidays. I think if you focus on other things (classes, rabid PIs, study groups, exams etc) it will be ok.