I'm an adult. Is it too late for me to learn?
No. There's lots of misinformation out there, that adults can't learn new skills, that they don't have the flexibility in their joints, or whatever. Adults can find starting an instrument from scratch a frustrating experience at times, because we're so much more self-aware than young children, and tend to worry as soon as we make a sound which isn't quite right. However, as long as you're prepared to put in the regular work that's needed, there's nothing stopping you.
But I can't read music.
You'll learn! This is one of the skills you'll be taught while learning the instrument, so don't worry about it.
I played the violin when I was at school, but then stopped. Am I able to start up again?
You may be worried that you'll have to start again from scratch, but you'll probably surprise yourself with how much you'll remember, and we can quickly get you back up to speed. It might be that you now have a bit more patience than when you were younger, and are able to focus harder on getting some of the technical details just right. This will pay dividends in the way it'll let you improve further with confidence.
Would I be your oldest pupil?
Probably not! There's plenty of people who have decided to pick up the instrument at a later stage, or who have neglected it for a while but have come back to it.
I already play the guitar/piano/etc. Is it a good idea to start learning another instrument?
Yes. I started playing the tuba three years ago, in part to develop my understanding of instruments which I knew precious little about, and am thoroughly enjoying it!
A lot of the skills you have developed with another instrument will translate straight away, particularly if you're already comfortable reading music and have developed good aural awareness. Guitarists often also find that their finger strength and dexterity gives them a bit of a head start when it comes to getting things in place on the violin or the viola, there's just the small matter of having no frets...