We don't look at the investment of material, time, and effort in our successes and say "Wow - what a waste! I should have spent the money on something else. I should have done this that or the other thing." We warmly welcome this success and feel satisfied in the accomplishment. Often, if we are really lucky, we feel motivated to do it all again and hopefully kick it up a notch!
Mistakes, on the other hand, don't get the same warm embrace.
Mistakes get the stink eye.