Some of us in here have been training for more than 30 years. Lots of over 40 guys in this thread doing great work.
Way too many former athletes let themselves go as they get towards 40. Of course life gets in the way, family, job, etc.. I say BS to that. Those things may be enough to keep you from being a competitive bb or powerlifter but they aren't enough to keep you from staying healthy and strong.
If it is important to you, you will find a way. I put together a pretty nice powerlifting set up in my basement because I didn't have enough time to drive to and from the gym and wait for a bench or power rack to come open.