Is 18 to late to start playing the violin?

Hi, i've always wanted to play the violin but growin up in a big family without alot of money it left alot of "wants" for us. I took up guitar in my early teens and have been playing it since but I really love clical music and the instrument itself so I was thinking of taking it up. But with the violin unlike the guitar I see alot of people saying you have to start at a rediculously early age to be any good, like 3 or 5. And to be honest it's just kind of turning me away from the instrument, not alot but it kind of makes me feel like it's a waste of time, I mean I dont expect to be a violin virtuoso by the time i'm 20 or even 25 but i'd atleast like to think I could get to a good level of violin playing, not playing twinkle twinkle little star 5 years down the road. Just lookin on some feedback, personal experience, is what these people say true or just bull?(I do however understand that someone who started earlier will be much better at a earlier age and probably learns faster.)