Old age is about right
Win 3.1: no issues, Win XP: fine, Win 7: okay after a while, Win 8: where is all my stuff??
By the way, (I'm still very happy with DOS 5.0 (yes, that is the pre-workgroup variety).
I now work (in the day job) with everything from DOS 2.0 to XP Pro x64 and am not a complete PC numpty (2x motherboard swaps, reinstall DOS 6.22/Win 3.11, multiple OS upgrades, multiple HDD upgrades, OS to SSHDD migration etc, etc.)
I'm sure the average 17 yr old has no problem at all. Unfortunately, I'm from the ZX81/Sinclair QL (remember those??) generation......