Yes, I too feel this way, although I don't get that many assignments (the workload predominantly comes from making sure I learn the content that has been presented to me). That being said, I think this is more an issue with myself than it is anything else, because plenty of people have demonstrated that it's more than possible to make time for other things if you really want to. This is just something I personally struggle with and that can take its toll after awhile. When I feel like this though, I ask myself what I'd rather be doing with my life - and every time, I agree that the path that I'm currently on is the correct one. I think this highlights an important point: even if you're following a path that you want to go down, you're going to have times where you don't feel that passion and enthusiasm that you once may have felt about it. That's why it's important to constantly re-assess, and make sure that you're not at the point where you absolutely resent what you're doing, or that you'd rather be doing something else with your life.