You might endure a (short-term) unpleasant feeling because it's a side effect of something you think will also have (longer-term) desirable outcomes/makes you more like the person you want to be (for example, hunger when you're on a weight-loss diet). This is the reverse of wireheading (by which term I'm including present-day non-fictional implementations of the idea, such as heroin), which gives pleasant feelings but doesn't make you more like the person you want to be. (The fact that pleasurable things can have longer-term bad outcomes and painful things can have longer-term good outcomes is the very root of akrasia, isn't it?)