Devil vs Angel??

It is interesting how you can be your own worst enemy.
We had a workshop with a project today, and afterwards we went out for dinner and to shoot some pool. Suddenly I just got into my head, that no, NOW I have to go home, and I went home. Even before I had stepped out from the poolhall I regretted my decision, as I would have wanted to stay longer and shoot some more pool. But I could not turn around as I had already said bye to everybody. I have been upset at myself for quite a while after this, although now I don´t really care about my decision.
I just can´t understand how I can want two opposite things at the same time?