The vast majority of the active members of my RC are at least over 40, many over 50 and several over 60. We passed a resolution at this year's AGM to have membership fees for pensioners at the same rate as junior members. There are many of us who are intending to spend more time riding after we retire than we have been able to do during our working lives. Go for it!!! if you can find another sensible horse.
I too am 61 and bought a two year old TB filly last december! She was in race training but too slow.Have had a few 10 min rides on her and she has been fine. After a lovely Arab mare now as I lost my lovely girl last december and Arab's are incomparable.
So 100 times yes...go for it, you only have one life,live it while you can.Good luck in finding the right one.x