to be honest, lets take out the age factor here

I think the passion that you have for learning of what you want to play, and your abilities with learning have a lot more to do than age.

I used to play the alto sax in high school, i did not use to practice and had first chair always told if i did more effort i would be greater with it.... i did tried to play the trumpet but that was too hard for me.. . and i did try the guitar but i had trouble "getting the wrest positions" and all... But as Sratocaster sounds like they got that down pretty well (like your rocking cat by the way)
Personally with me I wanted to learn the Oboe but was told it was difficult, but none the less-- i wish I would had tried it back then...

With that being said, perhaps trying the Violin is not a bad idea, if you get too frustrated you can try something else right?

I always thought the piano would be awesome to learn, so much and style with diversity of music, can be played on them as well

whatever you decide- I hope you have fun