Self-dicipline: good and not-so-good

My on-line journal is not really going to be about writing. Rather I'll be musing about soul experiences, and maybe occasionally the spiritual too. But I did want to consider something that plays into all three of these, and that's discipline.
You may think 'lucky you' when I reveal that self-discipline isn't a problem for me. Having discovered -- and this is the same for many writers -- that my creative energy is best during the morning and from mid to late afternoon, that's when you'll find me seated at my desk.
I can stick to a diet if I decide to. I can do daily exercise, or choose thrice weekly, or whatever. This ability I put down to my years of ballet-training when I endured the physical torture of daily class (yes, there was exhilaration too), and learned to push my body ever further and harder.
And therein, dear reader, lies the danger. Discipline does have a negative side. I can keep going, and going, when that internal monitor is shouting 'enough already', and my angel is making windmills to signal 'Stop!'
Because I've learned there's a price to be paid for distorting my will, and that is, I get ill or simply suffer what I call a flat tire. Do you know the feeling?
So I try not to go there, and to use my self-dicipline judiciously. Occasionally I even take a couple of hours on a weekday morning to goof off. And ah, how good that feels.