I took it up 3 yrs ago myself. I am now 45 and it has been a great thing for me. I used to play basketball but could no longer do it anywhere near the level I thought was acceptable anymore!
A tennis facility opened just across the field from our house 3 yrs ago so my wife and I joined. She had been playing some before, but I had only hit around in the park on rare occasions. It has been really good for us.
I have met a bunch of really good guys that started the same time I did and are basically in the same age group (36-55) and we ahve a blast during *& after!) playing. My wife has met some good friends too, though there is always "more drama" with women's tennis (it seems!!!) than men's. I am fortunate to have met a bunch of guys who don't care who plays what. We made it to 3.0 state last year, and they did not bump up any of us up in the ratings except for 2 guys, so we are back at districts this year, starting this weekend.
I really don't play all that much besides our matches once summer season starts as I was on 2 teams in the summer), but in the fall/winter we have regular guys court time (in conjunction with Monday night football) and I play mixed doubles w/my wife as well. All-in-all a great experience for us, even when I am in a personal tennis slump as I have been the past couple of weeks!