The principle of not stopping when you’re stuck (writing, in my case) is hella important. Get unstuck first, or in the very worst case, work out a list of possible ways to get through the sticking point, before stopping for the day. When you’re stuck, your unconscious knows you’re stuck, and it’ll find an excuse to spend more time tomorrow watching TV, reading, playing around on Facebook until…oops! No time to write today!… instead of wading back into the deep mud. I may be talking about writing, but I’d posit that this is true of any creative process, any subject being studied, or any complex project that requires creativity.