I did a lot of sleep hacking in college, trying to sleep as little as possible so that I could spend time with friends, play video games, and (ostensibly) study.

Now that I'm working a job where I do overnight deployments, often work 12-14 hours days, and have a couple of kids who don't sleep well, I hate my past self for not sleeping while he could. You never know when circumstances will drive you into unplanned sleep deprivation. Doing it to yourself for low-to-mid-level time gains isn't worth it.