For number two; the limit for human learning and memory have not yet been found, and I believe number 3 'becoming forgetful with age' has been taken care of by the 'won't suffer from age related illnesses' in the opening premise.
I'm 43. I found my limit at least 15 years ago. I went to college for 8 years and I have 2 degrees (not bragging, just saying). Most of that information is gone. There is only so much information that my brain can hold and it's been full for years. Immortality wouldn't change that. Even if storing information in my brain was perfectly efficient (and I'm sure that it is not), it is only so large, so unless immortality lets me grow more brain space, I'm out of luck.
I'm about the same age and am in the same boat (but only 1 degree). Why can't I remember much of the information I learned in college but I can remember worthless trivial things, like the words to Adam Ant's song Goody Two Shoes which I heard in high school. How much capacity does a brain have and how do we determine what is saved and what is lost?
Then again, there's
this from Boing Boing. In summary they electrically stimulated a section of a guy's brain and he suddenly vividly experienced a memory from his past. I guess we can only speculate on the accuracy of this memory, though.
It could be that the brain stores everything, but the brain wires itself so that information that's repeated ("Don't drink, don't smoke. What do you do?") becomes more efficiently recalled, while the stuff you learned in college but no longer need gets tucked away like the Ark of the Covenant in Raiders. A zap of electricity in the right spot could force the brain to recall something. Wouldn't it be cool if we could do some kind of virtual reality of our memories?
Things are taught to us in a way that's easy to teach but not so easy to remember. What American who grew up on School House Rock can't recite the Preamble to the Constitution (though doing it without singing is another matter).
