You'll hear singers and artists often say, "The fans keep me going." It sounds cliche, but it's true.

I've done a lot of projects in my life, and I think the ones that drive me forward are the ones with fans. It doesn't take much; only about 1-2 genuine ones. They're the ones who'll email you giving dumb ideas you ignore, but are flattering. As per the YC handbook, it's better to find something that a few people really love, than something that a lot of people just kinda like.

I'd recommend finding a way to connect with fans as well. One of the best things I did for my furthest running startup is to add a chat. Our users set up a WhatsApp group to stay in touch, and I'd join them and hang out with them. When running a grocery or most kinds of businesses, you see the people paying you money, and they thank you or smile in some way, and that adds a lot to the motivation. Try to find a way to work that into the business, even if it's a subreddit.

Or try to go the other way around this. Find something that someone is annoyed or pissed about. Or if you're working on an idea in your head, find someone who wants to see that idea done. Hack a solution for that; doesn't have to be great, just proof of concept is fine.