Memory

We are continually amazed by Luke's memory. Not necessarily him in particular, but I just had no idea  a two-year old could remember things from months ago.  Very few people have any memories at all from this age, and if they do they don't have many.  So when Luke remembers something from two months ago, he's remembering something that he won't remember later in life.  He's not just a prisoner of short-term memory the way he was as a baby; but these long-term memories he's storing away right now won't stick for life the way many of them will by the time he hits grade school.  Can some cognitive scientist please explain?

Examples:

• Close to two months ago mommy accidentally pinched his chin with the bike helmet buckle.  To this day when either of us puts on his helmet he will often say, "Owee!  Mommy owwee!"  (Mommy will never live this one down.)
• Two weeks ago Jackson bit Luke's hand.  Just a little warning bite when he was grumpy and Luke was being a little too rough; it hurt Luke's feelings more than his fingers.  Apropos of nothing in bed this morning he said to us, "Jackson bite Lucas."
• There are words Luke hasn't heard in months that he suddenly pronounces perfectly.  Maybe he never said it at all in the past, or if he did, it was back when he couldn't really pronounce it right.  But suddenly presented with an occasion to blurt it out, he says it perfectly, or at least intelligibly.  A couple of weeks ago mom drove Luke to the bank near the doctor's office.  We hadn't been there or said his doctor's name in a long time.  But when he saw the building across the street he blurted out: "Look, mama: Doctor Hammer."  Yes, this is the place where he gets shots, and it's therefore especially memorable.  But there have been other, more random examples of the same thing.