Roman asked in the comments to "I'll Just Sit On This For A Few Days..." --
When you say, "I'll just sit on this for a couple days...", what do you mean exactly?
If you don't do this, bless your heart. And feel grateful for whatever work habits you picked up, and however you picked them up, because I reckon the majority of people do it.
Let's take an easy example. Let's say you're in your first year at university, and you've basically finished a final report for a class a whole two weeks early.
It's basically done. You've proofread it multiple times. You think it's pretty darn good; you're happy with it. Now, all you've got to do is format your bibliography and cover page to make them both pretty, and you can turn it in.
Many people at this stage will say, "Ehh... I've been jamming on this for seven hours in a row, it's pretty good, I'm basically done. I can leave the formatting until morning, and maybe I'll also have some other good ideas to improve the report?"
That's an incredibly stressful and costly habit.
By all means, if something is below the bar -- unacceptably bad quality for what you're doing -- yeah, revisit it tomorrow.
But if it's above the bar, you're doing yourself a huge favor by getting it done and in.
Once it's done and in, you can breathe a sigh of relief. If you have nothing else to do, you're now free to go laugh and dance and play. If anything goes wrong (and things very often go wrong in life), you don't have to be stressed, because the report is done and in.
The opposite way means you can't quite breathe easily; you still have work to do or you'll get in a problem. And if you happen to get struck down with an illness, or some other catastrophe, then suddenly you wind up scrambling for something that was almost complete.
The university example is even less destructive than most things in real life.
Professors have some clear guidelines about not being able to change assignments mid-course on their students. The commercial world isn't like that.
If you have something almost complete, but then a company you're working for, contracting for, or partnering with hits a cash crunch, has a hiring or spending freeze, or tries to change the scope/requirements on you, it can cause all sorts of misery.
There's plenty of times when something will be basically done, and people will say, "Ahh, I'll get to it later, it's basically done..."-- with disastrous consequences.
Heck, it's the whole point behind the Tortoise and Hare fable.
There's not even any good reason to do this; it's just a bad habit.
Pulling the trigger on something and finishing it is hard for many people. There's always a certain worry and uncertainty. I'm not sure the feeling ever goes away. But leaving almost complete work barely unfinished is a disastrous habit that leads to a lot more stress and problems in life. Get the report in, get the proposal sent, get the invoice in front of whoever is supposed to pay it, get the tax and license paperwork done at the earliest possible moment, and so on.
Easy to say. Harder to do. But incredibly life-changing.