Never too old! If your wife is a decent muso, then why won't she give you shove in the right direction. I play many instruments, and with your background, I'd

Never too old! If your wife is a decent muso, then why won't she give you shove in the right direction. I play many instruments, and with your background, I'd suggest learning to read music and playing a keyboard would be an easier start. Guitar is harder than it looks. Assuming that you type reasonably well, then you already have the finger dexterity to play a keyboard reasonably well. Once you can play some bass lines, the two of you should be able to jam. That in turn speeds up your learning and increases the motivation. Good Luck!