Maybe if you saw him casually, it just was not that deep, or something you were not interested in.
I can think of so many reasons (and memory normal, with that time difference) about why you would not remember... that do not involve mental illness or hardships of the time, but instead are just about how long you saw each other, that it was bit of a time ago, and that it may not be the deep kind of therapy digging into trauma is (so would not stay remembered much, either.)
I mean.... forgetting is normal. It is those memories NOT being forgettable, at all, and relived, and all, that is the difference. Just because remembering vividly is this disorder normal does not mean some times, healthy people standards will not still apply. :sneaky: