I bought some Mexican spiced mackerel from Tesco and ate it for tea. AIBU to think that it tasted of....well....mackerel. I was really disappointed! It was supposed to be spicy with a citrus kick. I was imagining lime and coriander with chilli etc etc. It was just....mackerelly with the smallest hint of lime at one point. 
Along with my AIBU, what have you eaten that left you sorely disappointed??