Spiritual Ruminations: fasting and abstinence

I was just thinking that one of the reasons fasting and abstinence are such powerful spiritual weapons is that they stump the demons.

Fasting and abstinence are mortifications that one imposes on oneself, like the donning of a hairshirt or flagellation. Unlike these last, however, fasting and abstinence essentially involve, indeed consist in foregoing things that are good in themselves.

Since demons are essentially self-indulgent (though like any true narcissus, a demon is capable of enormous seòf-deprivation if he can see the potential benefit for himself in it), they must be terribly confused by somenone's skipping a meal or taking a pass on the steak or keeping the cork in the bottle, especially when the discomfort incurred or the pleasure foregone is offered as penance for the sins of another, maybe even a stranger.

Thoughts, anyone?