Actually I think what you have to worry about is the other end of life, old age. If we were to make breakthroughs in medical science and start to produce people that even had a couple of hundred years of life, it's not clear to me that our brain, mind and social bonds could cope with that length of time, and that they would need to undergo evolution to balance this out. Could a human brain really hold five hundred years of memories, never mind thousands? Or would it be a crazed mis-match of randomness?
Now you did it. You provoked me to regurgitate long debated musings of my own mind.
So you might want to skip this
Just brainstorming, but
what if, what are often called 'gifts' such as having an almost instinctual ability to work out mechanical problems, work wood, create art, mathematics, etc.-- or precognition-- perhaps even some forms of insanity (schizophrenia) and so on...were not just un/lucky combinations, but, memories and knowledge handed down from prior generations?
IOW, at the moment of conception, all of the knowledge and experience of your parents 'at that point' were encoded into the DNA (or whatever) that formed you. Along with it is the knowledge and experience they gained from their parents up to the point when they were conceived, and so on going back to the dawn of time.
Skills and abilities passed on and built upon by each subsequent generation. Precognition/déjà vu/instinctualy knowing who to avoid or how to react in social situations, not so much some magical ability, but millennia of experience allowing you to subconsciously 'guess' or predict, calculate, what is going to happen to even having knowledge of previous similar events or places. Certain forms of insanity, where those memories, thoughts, and so on, push their way due to a defect into your conscious mind either confusing or conflicting with current reality.
Naturally, not being knowledge you could directly draw from, that forefather experience and skills would reveal itself through 'inspiration.' You don't know why, nor have been taught, yet, you seem to just know. I would also suspect that over time that access to such knowledge degrades or is veiled as we heap on our own experience and knowledge tending to look to them for guidance instead of letting that of this passed down experience flow freely.
Clearly as we see with dementia and alzheimer's patients who regress drawing out long forgotten memories that we actually forget nothing, just stuffing it away. So there is the ability to shield (not eliminate) impertinent 'formative' information. Leaving the only question of, could it be handed down genetically?
If so, then I would say "yes, the human mind could hold thousands of years of information." I suspect that knowledge is not limited by the constraints of a physical size (number of cells, size of your noggin (your avatar regardless), whatever).
I warned you not to read that
K2