I'm frustrated because of Field Theory

[Amanheis]

I'm now in my fourth year of physics and taking QFT right now. I always was quite OK gradewise at my german university, had a 1 (=A) in my pre-diploma, was among the best, and thought I can do what I want to do, which is fundamental physics. Right now I'm in the USA. Every teacher I had was strongly advising that everyone, even those who want to be experimentalists, attends a QFT lecture. So no question about it for me since I'm interested in theoretical physics.
But right now I can't see how anyone but the best of the best are able to succeed in such a class. Our teacher is basically covering everything in Peskin/Schroeder and I'm reading the fourth chapter right now and I don't understand a single word anymore, not to mention being able to solve the problems. When I close the book because I'm frustrated it gets even worse, because it says "Introduction" on the cover. I'm wondering if those who I look up to, my professors and teachers, ever struggled like me, since I wanted to pursue an academic carreer too. But right now I am doubting if I even can achieve a PhD.
In my GTR class last year there was no exam, but I seemed to do fine. I don't know if I am lacking the basics or if the Peskin/Schroeder is just not suitable, but I don't how to master this whole topic.

So I'm in a little crisis right now. Maybe some of you have some advice about better books or a better technique, I don't know. Perhaps I just reached my limits, which would crush all my vague plans about the future.

 

[jostpuur]

I tried learning QFT from P&S on my own, already before I took the first QFT class. I did not feel like understanding much, and after enough struggling I lost my confidence in the belief that professional physicists themselves understand QFT.

I took the first course on QFT 2007 fall, and I had decided my studying technique to be this: "Learn to calculate like the lecturer wants you to, by doing exercises, and don't worry about else. Don't waste your time trying to understand QFT. Those who feel like understanding it are bluffing."

Well it worked in a sense that I got top scores out of the course, but on the other hand I have already lost my interest in becoming a theoretical physicist, and I have mathematics as major now. So if you are serious about theoretical physics, perhaps you shouldn't try it my way. But that could be a temporary solution on surviving the QFT course, if you don't have any better ideas.

 

[atyy]

I think Peskin and Shroeder start with canonical quantization then do path integrals later. Albert Stetz has a nice introduction, but presents it the reverse order, so probably cannot be read in parallel to PS:
http://www.physics.orst.edu/~stetza/Book.pdf

Kyoungchul Kong has a nice list of QFT notes, of which I like Eric D'Hoker's particularly (listed as QFTA.pdf and QFTB.ps):
http://www.phys.ufl.edu/~kong/Notes/
http://www.phys.ufl.edu/~kong/Notes/QFTA.pdf

 

[will.c]

Physics is hard, and quantum field theory is a professional research tool, at the cutting edge of what physicists actually do. If the course is frustrating you, follow jostpuur's advice and for now just pass the course - but nobody is a QFT expert after (during?!) only a year of study. Presumably your professors are more than a year your senior, in which case you can expect to be that knowledgeable when also you get to be that old!