hnbd
When I was in elementary/high school, I got into programming purely through an interest in reverse engineering and writing hacks and bots for online games. My interest in it allowed me to get through reading assembly and complex C++ memory injection code that was way beyond me at the time and learn from it.
Reading and understanding large code bases is not an easy thing. When I started my first job at a very large enterprise software company working on a 20+ year old massive code base, I had some serious anxiety when I first looked through the code. But take your time exploring it and trying to understand it, look things up as you go along, and you will eventually start to understand it.
Write some code with a purpose!
Ideas are great but what's better is an idea with a business plan; especially to an investor. This is especially the case if your idea doesn't clearly identify a revenue source. Unless you have a reputation or history creating successful start-ups, you shouldn't expect to just have someone take your word and believe that your start-up will generate revenue. There may be investors out there that just take chances like that...I wouldn't know. But I still fail to see the fault in his expectations I guess.