I hear that a lot in the startup scene where I live. It's bullshit.

First and foremost, an idea is never world-changing. It's the execution of the idea that changes things. Until it has been executed successfully and actually changed the world, all it is is an idea. The impact can only be assessed later.

Secondly, most people don't have ideas that will make "other people's" lives better for some nebulous concept of "other people". Ideas that work are born from problems you see every day - usually pains that you suffer yourself, but equally pains that you see your loved ones or co-workers struggling with over and over again. Unless you have direct, first-hand experience of something it's very difficult to see a way to solve it because you don't know what will make it better.

It sounds very much like you're putting yourself under a huge amount of pressure. Find a way to stop doing that. Find something that you think will be interesting, fun, and will also contribute to the social good and make the world a better place for a few people. If you're working on something that has real potential, other people will soon start to put the pressure on for you.