No Zen

I didn't go to zen tonight. I got home from work really tired and I took a 'nap' that lasted over an hour. I woke too late to go. This difficulty in doing what you 'say' you want to do and know is good for you has troubled me for as long as I can remember. I guess it is a fact of the human condition since many people I know voice this concern also. But why? It seems to me that if I could understand and circumvent this annoying propensity, I would accomplish a lot more in my life.