Ask HN: How do you keep yourself motivated to work on an idea?

I have lots of ideas but I find myself switching from one to the other very easily. This way I will never fully commit to one idea and I've realized that you need at least a few years till your startup becomes truly successful.

I'd be grateful if the HN community could help me out and share a few techniques as to how to keep myself motivated and keep pushing on just one idea, day after day, month after month.

Thanks!