I am 47 and I started about a year ago. I had to grind out the first song and the first song with bar chords rewired a good section of my brain (ouch).
I started on another site like this one but I ran across this Guitartricks and it seems to be more complete and have more structure.

I started because I wanted something that I could do and enjoy just for me. I also needed to take my mind off of work and sitting in front of the TV never did it. I found out that when I practice it requires complete focus and the minute my mind strays back to work or anything else the guitar makes a horrible sound! That's when I know I need to focus on what I am doing and not thinking about something else.

I am not sure where this will all lead but it adds something creative and different to my life.

Darrin