ofey wrote:I'm a little nervous when I show up and they are expecting a fresh faced teenager and they get a 25 year old scruffy dude.
Don't worry. I intend on starting grad school in physics next year (at the best school I can get into). In two years, our ages will be in the exact ratio of 1 to 2. I will stand out. On the other hand there will be plenty of new grad students your age. For example, one guy I knew spent a few years as a lumber-jack in Canada before going to physics grad school and getting a PhD in small scale experimental physics.
You're going to be assigned a desk in a room with a lot of other grad students. They are going to talk to you. Some of them will be taking the same classes and even if you don't talk to them, they'll ask you questions.
Physics grad students (from what I recall) are very social. Often you will go as a group together to eat lunch. If you're near a beach, you will go together as a group to sunbathe or (on the west coast) to watch for the "green flash". People who have cars will offer you a ride when a group decides to go to the movies.
As far as socializing with the professors, again don't worry about it too much. Classes are going to be much smaller than you may be used to. It will be impossible to not meet the faculty. In addition, there will be a weekly "tea" where they feed cookies to grad students. At some schools, the grad students will be assigned the task of running these things. At many schools your attendance is mandatory.
In addition, research groups will have weekly meetings. Even if you're not technically accepted as a part of a research group you can show up at their meetings to get an idea what goes on there. For example, I dropped by the physics department at UNM and a professor invited me to sit in at their quantum information group meeting (which was the group I was interested in).
Now my memories of physics grad school may be somewhat dated. If things have changed, it would be because grad students are making so much money nowadays that they don't HAVE to socialize. But the people who show up at physics grad school will be intensely interested in physics. You will discuss thermodynamics and statistical mechanics puzzles over pizza -- not only because you're going to have to pass the qualifying exams, but because everyone will be fascinated by the subject.
Believe me, for once in your life you will be surrounded by people who are monomaniacs interested in the same subject as you. Grad school is like going to a 6-year Techie or comic-book convention (if you're interested in those things). You will have something to talk about with literally everybody you see and this will go on for years. You're going to have a blast. Don't sweat the social stuff.
Physics grad students are happy except for tough grades, unfair qualifying exams, mean or unavailable advisers, and the usual sexual drive problems of youth.