I mentioned this to my psychotherapist and the consultant that did the assessment. I did not get an answer, but I don't think this is normal:
Especially when tired, I can get a bit emotional if I think of certain things. I'll then think I really want something. But I'll wake up in the morning and feel nothing and not care. Alcohol causes issues the next afternoon, causing more emotions.
I asked someone at work. I think normally when you calm down or wake up the next day you still have the emotions, but toned down. So you still know you are interested. It's like I have a threshold things have to reach to be noticeable. By which time they are ramped up quite high.
Without consistent emotions I find it hard to know what to do. This also confuses other people
I looked at an emotion wheel, and I think I know what all the things round the outside feels like, so I must have felt them at some time. Unless I iintellectualised it, but I don't think so.
I did the TAS-20 alexithymia quiz and got 66, which is interesting. According to Wikipedia 50-85% of autistic people have alexithymia, compared to 10% of the general population.