Recently, I have been asked to conduct some training for a client and the sessions have been immensely rewarding. It's great when you see people learning something new and realising what a difference it will make to their work.
It is not the first time that I have been asked to give training sessions, but I had forgotten how much I enjoy it. The key to success for me is being thoroughly prepared - what used to throw me was being asked to present slides that I had not written. Winging it is not an option.
Is there an area of your working life that you feel is under par? Get out there and test yourself. You could be surprised, and if you were right about needing a boost then try to find a course that will unlock the mysteries.
Yes it's a bit of extra effort, but the returns are worth it in increased skills and self-esteem. A dog is never too old to learn new tricks, in my opinion.