It’s difficult to know what counts as sugar.
Indeed. You probably know this, but it seems that every processed food in a typical grocery store has a sugar of some kind, often as one of the top four ingredients. Glucose, high fructose corn syrup, sucrose, etc.
I'm not sure if natural matters, either. I get equally bad sugar reactions (throat clearing, appetite enhancement, napping, irritability, joint pain) if I eat an apple as if I eat sugar.
I try to follow the rule of "no added sugar", so I've stopped adding sugar to my tea and my cereal. I haven't had a soft drink in ages.
I do like ice cream, though; it doesn't seem to give me as many of the negative effects even though of course there is plenty of sugar in there. I think I don't have sugar cravings except for ice cream. (I know. "Other than that, Mrs. Lincoln, how'd you enjoy the play?")
As far as your "special occasion" comment goes, I'm trying to move to an attitude where food is not celebratory or a reward for anything and is instead just fuel for my body. If I start wrapping in things like rewards, boredom, social cues, fatigue, and so forth, then that moves me away from my "eat when hungry, stop when full" mantra. Those other things create - for me at least - a relationship with food which is less healthy.