Last time I rode trials was around 15-20 years ago, then I rode bmx for around 10 years then stopped about 8 years partly due to starting a family and partly due having an injured knee.
I had a real itch to ride again though so tried getting back into bmx twice mainly because that's what my friends rode but to try cut a long story short, I had too much fear. I've always still had that itch to get back into trials, especially after Danny's 2009 came out so got back into it last February and loving it. The great thing about trials is you can practice it anywhere.
I ride with a great bunch in Aberdeen, we are all fairly similar age, 40'ish, we all push each other but ride within our own limits.
That would be the best advice I could give, ride within your limit but push it when you can.