Emotions just are; I don't think they can mis-function. Our mental interpretation of what our emotions are telling us and how we express them is what we may have trouble with.

There is no "should" on a date; if I get date raped, I'm going to be anxious on every date thereafter until I fully deal with what has happened to me (and maybe afterwards). If I think I "should" be having fun, I'm going to be at cross purposes to what my emotions are telling me and to my past experience. That being so, it's possible to set myself up for another bad experience because I am ignoring my emotional information and not keeping myself safe and/or sharing my experience and helping those around me be careful of me too (when one breaks a leg, it gets casted and those around one make sure not to bump one and offer help; if I tell a date I am anxious/fearful because of previous dating experiences, he probably is less likely to do or say anything startling/potentially upsetting).

For me, abnormal is not taking care of one's self by checking one's perceptions of self, others around us, and situations we may be in (being "present") or responding inappropriately to the intellectual or emotional information we are given (laughing at a funeral service and not removing ourselves from the situation; it is not abnormal to feel like laughing, but it is inappropriate to remain where most others in the group might be disturbed by the laughter).