I turned 43 this year. Last spring I picked up a 2003 XR250R, and started riding in the dirt for the first time since I had a Honda 50 when I was 8. Rode it 5-10 times and did my first enduro, 58km of nasty single track, fireroads and ATV trail. I never won my class, and I never finished last. I did have a blast, and had a permanent grin for days after.
You are never too old to try something new.