Titles
All of us are good at rationalizing...
It's easy to rationalize why we did something or why we didn't do something.
I have read of a Mark Twain quote, wherein Twain's neighbor asked to borrow (a ladder?) and was told by Twain, "No, because I'm having soup for supper." At which the neighbor asked what soup for supper had to do with the ladder. Mark Twain answered it didn't have much at all to do with the ladder, but when you don't want to do something any excuse is as good as another.
I would have preferred to have found the actual quote to use, but the search has not been fruitful. And it is such a wonderful illustration for this point.
The second point that should be made is that reality doesn't care. If you decide not to do something...say you decide you don't want to make a house payment this month, or a car payment—or go to the gym, or whatever, the natural course will happen.
That may mean you lose your house or car, get flabby, or if you decide to take up roller skating late in life there is still gravity that will probably catch up to you. Reality doesn't care if you're having soup or not—but you may not like the consequences.
Aim for the things that not just make you happy, but in the long run will make your life better and more prosperous.