[xiaoma]

I'd look within. If you just ask us, you won't actually have the insight.

What in life have you personally been frustrated with? What made it frustrating? What it didn't have to be that way? What would the better version of the world look like?

If you can't think of anything, then I'd get out and live more and study some along some tech-related path. The first will help you understand more of the world is and the second will give you more ideas about how the world could be.