Is it ever too late to learn?
I have heard this from all ages. The short answer is, if you have a goal of learning to play the violin (or viola or cello) and you set realistic goals, it is never too late.
I had an elderly student that must have been in his late sixties or early seventies; I never asked because it didn’t matter. He had an injured shoulder from multiple rock climbing accidents through his life (I did compromise on my insistence of perfect posture - it was not realistic in this case), big arthritic knuckles, no ability to read music, and a burning passion to travel to Ireland and play some jigs in the streets and pubs.
I got him started with playing and reading for half a year and then I had to move to a different state. After about another year of hard work on his end, I got a thank you card in the mail which included a picture of him in full Irish garb, happy as a clam, playing jigs on a street with some other musicians.
If you think you're too old for starting a new instrument then you are, and you'll find every excuse in the book to not start. If you feel young and have a can-do attitude again then it is never too late. Find yourself a teacher who will help you with your goals.
One other point: I always wanted to play violin. As part of my music education degree, I had to play all of the orchestral instruments. Along with a complete inability to play oboe, getting me to practice any of them is like pulling teeth. That is, other than the stringed instruments. Giving someone an "easier" instrument isn't always going to satisfy the urge to play music. Especially since easier is different for everybody.
So, what do you think, are you too old to start learning a new instrument, or do you still have a sense of adventure?