About alias, I do not agree. I think "as" is the way to go. It's standard and everyone understands it and you don't risk confusion, it also does not take any more time to write "as" than "=", if anything "as" goes faster.
About aging, it's been proven recently that people over 45 solves equations a bit more slowly than younger ones.
With that said, I feel some people now must raise their voices to redeem themselves and point to that experience and knowledge holds a high value as well and I do of course agree.
Also, it's common that engineers has an iq around 125, thus giving an advantage still over the general population, not that it matters except you have the ability to claim a more interesting job and complete it.
Then about learning new things, I do not think that has to do with age. I firmly believe some people are more interested and might also be better at grasping new concepts than others. It might just stand out more when someone who is old is not interested to learn. Then there is one more thing I'd like to point out, science has proven that our brain actually hurts a little when we learn new things and this might be a cause for pointing us towards old habits. Then of course some people are just plane lazy.