I'll share my story so you'll know how
not to do it.
I was eleven when I saw the Beatles on the boob-toob. It looked like so much fun. Being the third of five kids, my folks had already been down the "I wanna play an instrument" several times before (both of my older brothers were two-time losers).

So now
I had to justify my interest ("I really really REALLY wanna play the drums!") Wait - what?! Yea, I wanted to be a drummer before I wanted to be a guitarist. So I nagged, and nagged, and nagged some more. I was smart enough to know that I shouldn't make like a living hell for them - just a constant irritation.

They relented and allowed me to rent a snare drum. I signed up for band at school. Life was good.
I actually was pretty good at it. My buddy was also in the class and we regularly competed for First Chair. We were neck & neck and it got to the point where we would alternate 1st chair, 2nd chair. At the end of the semester I realized that, although I was proficient at it, my heart wasn't in it. What I really wanted to do was play guitar.
Drat! Now I had to convince my parents all over again!
My rationale was that I did good and stuck to it and 'proved' my commitment to one instrument, so that commitment should be transferable, right? Mom was amenable but dad balked. He had spent too much in the past on instruments that were just languishing in closets for him to be amused at the idea of shelling out for another one. So the deal was that they would reclaim my eldest brother's guitar and I would 'prove' myself once again.
So my first guitar was a hand~me~down Harmony complete with authentic painted fret markers and big-azz strings that hurt my fingers. what I didn't learn until a bit later was that it was a gut-string guitar that someone had put steel strings on and fractured the neck. How I learned this was through my teacher getting mad at me because I was too retarded to tune my guitar. It wouldn't tune because the tighter you wound the strings, the more the neck would bow.
It was the second most frustrating thing I ever went through (my 2nd marriage being the first). I couldn't make the damned thing do anything without sounding like a drunken dog - and lady gaga wasn't fashionable at the time.
I needed a real guitar but I was losing the race on the old one. I went ahead and signed up for a 2nd semester of drum band, and guitar classes too. I dropped out of the guitar class because I appeared to be too stupid to learn. When he told me about the neck it was already too late. I finished the year in band and dropped the drums. I spent the summer trying to fix the Harmony and my folks took pity on me and decided to buy me a 'real' guitar for Christmas.
My dad took me out to pick one out. We went to several stores (keep in mind that 1. these stores are miles apart, 2. it's Christmas, and 3. there were limits to my dad 's patience). When we got to the "This is the last G-D place!" store I looked at what they had and there she was - a 12-string dreadnaught guitar. It was the most beautiful - and exotic thing I had ever (in all of my 12 years of living) seen. "That's the one I want!" I exclaimed.
"No" was all he said.
Bummer.
I looked at the rest of them and then did what was likely the hardest thing that I had ever (up to that point) done. "Let's go" I said. "If I can't have that one then I change my mind and don't want one at all".
The old man looked at me more seriously than I think he ever did before. "Are you sure about this?"
"Yes, I am"
I swear to God he counted to a hundred for dramatic effect.
"Then it's yours."
I still have it.
I played it this morning.
Thanks Pop for believing in me.
Edit: altard proofed