I think this is really important, because pushing through on one project that's not working makes you neglect other projects that are more deserving of your tim

I think this is really important, because pushing through on one project that's not working makes you neglect other projects that are more deserving of your time, attention, effort, love, blood, sweat and tears. Opportunity cost. I had a really compelling but unproven idea once, for a gap in the market for a library. I made an absurdly ruthlessly minimal prototype in 2 hours; then spent 1 long day (9 hours) making a website. My rule was if no one appreciated it in 10 days, I'd forget it. Someone did, and it ended up making me ramen-FU-money.