Why can't I ever just quit while I'm ahead?

So I was playing with my new paint last night.  Now I have a weird way of painting I guess.  I never have a clear cut idea of what I want to paint and what I'm painting often changes many times during the process.
This is how it usually works..I paint something...don't like how its coming out, wipe it down..look at the colors and patterns that are left and go from there...and many times I will paint, wipe down, repeat about 2x.  A waste of paint? I don't think so because I don't wipe all the paint off..i just sort of blend everything on the canvas slightly with some water and it becomes an under layer.  And usually i love the end result.

Then there are times like last night..when I get a painting that I like but keep messing with it when I should just walk away and I mess it all up...and then wipe it down angrily and try again....
Last night I had a painting that was going in a direction that I really liked, but I should have walked away let it dry and overpaint any other detail later...but I just wouldn't leave it alone.  By the time I was done I had a mess of a nasty canvas with thick muddy looking paint, and was very frustrated and just uuggg!!! lol
Used a palette knife, scraped the canvas as clean as possible.  It was like an artistic meltdown last night ...I wish I would have taken pic of the canvas last night in different stages.  Just one of those nights where the muses weren't working quite right and i just couldn't get it together..Ah well today is another day :)
So here is a cute little painting I did on a less frustrating painting session last month