I agree, that there are different levels of understanding. To e.g. fully understand the USB enumeration process, you preferably want to observe it in a real hardware setup, having either a hardware USB monitor or a software monitor running on the PC. Descriptors have different complexity depending on the involved device type.
But is it a good idea to say it's all too much? I would rather say: I'll do it and focus on the basic things. If you say 2 weeks, you'll get the same problem on a higher level, I guess.