I was already old when i designed my System/room acoustically using only my ears/brain as a tool. No it was not perfect for all others ears but perfect for mine (surrounding sound from a stereo system with holographic sound instrument volume).
i had 74 in few weeks, i designed my walking stick with a branch given to me by the river and i walk more swiftly with it.
We will not die, the body will stay still one day...
Music exist eternally as the primes numbers music which contain everything...
I will perhaps upgrade my low cost well optimized speakers for my birthday...