My 7 year old seems to have problems remembering recent events. he tells me he cannot remember. what could cause this. is this normal?

Hard to say: There are rare kids with deficiencies in memory that can be verified by testing. There are also kids who function at less than optimum because they are sleep deprived, ill or just don't pay attention. Saying you don't remember is easier to do than admit you didn't want to do something or were preoccupied. At 7 it is not the same as a lie at 12 (maturity). A doc visit may help you sort it out.