What eating ice cream does for some people, besides giving them pleasure, is provide a feeling of serenity. The serene person is one who is not affected by what's going on around him. In other words, he's in control of himself. And, as might be expected, he doesn't experience a feeling of being controlled either. Serenity is a lot like the feeling of being a hero that heroin addicts experience.
Heroes are people who are in control of themselves.
Otherwise, they couldn't be in control of the situations that allow them to be heroic. You certainly do run the risk of becoming addicted to behaviors that give you pleasure, however. But what would actually lead you to becoming addicted to one of them would be its ability to get rid of a chronic feeling of being controlled and then to make you feel in control of yourself besides.