What gets people off the couch and into the world?

Inspiration.

This is part of our human machinery that is always running. We constantly become aware of things we want, and actions we could take, and then reasons why we shouldn't.

It's an ongoing conversation that never stops. I want X, so I could do Y, but then Z might happen.

There are gazillions of examples where we say "What the heck, I don't care about Z," and do it anyway. That's all the stuff that gets done in the world. All of it.
And of course there are gazillions more examples where we say "Oh, dear, if Z happens that'd be simply awful, so I won't do Y." Sometimes we go on to think, "But Y is not the only way to get X. Perhaps I could do A, or B, or C." This is just another iteration of the same process. We either do something or we listen to our reasons not to.

I have found it enlightening to actually pay attention to that conversation in myself, and become aware of my common reasons for not doing things I want to do. I have noticed that THE MAIN REASON that keeps coming up over and over for me is "Someone might criticise me, or get mad at me."

That is so funny to realise, because I would have insisted that I don't care what other people think. Most of my friends and family think of me as something of a social daredevil who does his own thing in spite of other people's opinions. This reminds me of the movie Batman Begins, where he grows defiantly in the direction of his greatest fear (bats).

Anyway, that is the most common thing that stops me (keeps me on the couch). What gets me going again is seeing someone do something or hearing about something that inspires me. Inspiration calls forth the behavior of taking risks and working hard to achieve something we want.

I noticed another common reason that stops me is "It won't be fun." Someone in there thinks I'm supposed to only do fun things. Another is "It won't work." Yes, possibility of failure, even without criticism, is another great reason for me to stay on the couch.