Something in motion will stay in motion until acted on by some force. Similarly, something at rest will stay at rest until acted on by some force. Very logical. I think it applies to humans too.
Ever been sitting down, trying to avoid some work that you know you have to do? Never happens, I know. It's kind of funny, sometimes I spend more mental energy trying to avoid it than it would take to actually go do it. Luckily, sometimes all it takes is actually convincing myself to get up on my feet and then I am motivated enough to go do it. Might as well, I am up now, and I am not going to want to do it later.
Stopping my rest, getting up to go do something, anything, is where to start. Even with something totally unrelated, sometimes lets me keep enough momentum to go do the thing I have been avoiding.
The worst part is the things that you want to do, but, for whatever reason, you just don't. You feel like you don't have the strength or creativity or whatever mustered up right now so you just keep avoiding it. The good news is that momentum works here too. Once you get moving at all, take the first tiny step, get one little thing done, you've got it. Now you're in and you have momentum to continue, that's where you want to be.
Conversely, once you are indeed moving, it's hard to stop. You want to finish, get this one thing done, then you want one more, and you have to finish that... and it goes on. This could be good... or bad, depending on what it is. It applies to more than just chores and projects. You have to be careful what you start. Once you take the first step, you're moving. After that, it's hard to stop.
Just one more game! One more chapter! It's way past my bedtime, but oh well. I'm here, I'm set up, I'm having fun. If you really need some sleep, best not to even take the first step tonight. Or at least set up a force that will stop you later.