is 15 too old to start playing guitar and becoming really good by 20?

If anything, it's better than starting as a kid because you're way more focused when you're 15 and it's something you're choosing to do rather than being forced to by mommy and daddy. I started learning piano at a later age than most "prodigies" (I started at 11 when most kids start at 4 or 5), because it was something I chose to learn rather than being forced to I learned way quicker than other kids. After 2 years of playing, people thought I had been playing for at least 5 years. Now that I've been learning for 7 years, I've made more progress than some people after 10 years. If you're going to commit to it, it won't be hard to become good.

I've also taught myself guitar, and really it's not that hard to sound decent at it, so after 5 years you should be great if you're focused.

That's a perfect age to start. With a little help, you can hit your stride in five years, and have a lot of fun. Whether or not others will consider you "good" then is a different matter, but I can guarantee that you will play way better than those who never tried.

Yes, get some help, otherwise you will "practice" with little gain. Ever see "Jake" in Two and a Half Men "practice" Smoke on the Water? Or "Daniel Larouso" trying to learn karate from a book in the first part of Karate Kid? Get your basics going, and get help from real players. Go for it.

your never ever to old to start to play the guitar

it's never too late you could be good at it by the time your 20 if you really stick to learning it and enjoy playing

i started when i was 16 now i am 19, i am good at it, i even teach guitar, it depends on your practice, i practiced alot. if you want to do it then go for it, i have seen people who started at 30 and are very good players.

no

No!!!!! You can defiantly become a really good player by 20. Just practice and work hard and if you really want to become a great player you will

of course not! However, the only way you'll meet that goal is... you might wanna sit down for this... PRACTICE. Everyone says it, but it's extremely important. You can do it!

Hell no! Depending on your level of dedication and talent, in five years time you could be very good. (Or you could be like me, started at 11 and now I'm 54 and still trying to learn the damn thing. )

Now pick up that guitar and get to work!

That's when I started playing guitar, I'm 16 now and pretty good at it

Yoire never too old to start doing anything.