I have always picked up things because I have found them interesting but the sense of guilt of not doing enough plagues you when you see success and recognition of other people in those fields.

For eg, someone who didn't waste his time during grad years and was able to complete many awesome things, fetched a job that I could only imagine. Lately, I have been avoiding going out on weekends, because "I have to do build something for world to show". Has this been helpful? Yes maybe, but not certainly, "very enjoyable".