I don’t have commitment issues; I just can’t say no to a better offer

A plausible excuse?

Or does commitment really equate to saying no vehemently to better offers?
Is that commitment then, out of obligation, without true intent?

I don’t know. I am hardly commited to any cause, or to anyone. I live for myself, and while I promise myself, as well as other people, things, I hardly treat it like I’m committed to fulfilling these promises. Sure, a promise has to be realized, and that’s where sometimes genuine desire turns to obligation. So is commitment a promise?

Is commitment measurable? How is it judged?
Say, a man mentally cheats on the wife (i.e. fantasize about some other woman). Is that lack of commitment, or must it be something physical, that can be shown and proved? If yes, then is it fair to say that commitment, in the worst sense, equates to physical enslavement, where it is imperative that one does certain things as promised, but not mental enslavement, since one still has freedom to thought?

So, is commitment obligation?
When is it genuine desire and when is it not?

And this word, commitment. It cannot be translated, clearly showing an Anglo belief system which I refuse to impose unto myself.