I'm about to start a PhD program at a top 5 school but I'm just not feeling excited about it. I feel burnt out and I've lost my enthusiasm for physics. As an undergrad I worked ridiculously hard and sacrificed my social life for physics and I just feel like I can't do that for another six years. I always hear about how hard grad school physics is and honestly if I have to work harder than I did as an undergrad I'm almost certain that I'll drop out. This summer I've been at home all summer for the first time since high school and I've been having a lot of fun with my old friends from high school and it's just making me not want to go back to school. I worked so hard as an undergrad that I never really made time for friends and never developed a good group of friends and I miss having a real social life so much. Part of me wishes that I had just gone to the local university for undergrad and majored in engineering or something and just gotten by on my intelligence and had a great time rather than working so hard and having no life. I feel like I've missed out on so much in life and I need to make up for lost time. If I weren't going to a top five school I would probably call it off and find something else to do with my life instead of getting a PhD in physics but I don't want to throw away an opportunity like this in case this is just a passing phase. Has anybody else felt like this when starting grad school? Can anybody offer me any advice? At this point I can't really back out of it. I guess I'm going to go but there's no way I'm willing to continue working as hard as I did the last 4 years and I can't really see myself making it at such a tough school without working hard since hard work and not necessarily being all that intelligent is what got me in. Compared to the average person on the street I'm a very smart guy but compared to PhD students at one of the top universities in the world I think I'm on the lower end of the intelligence spectrum.