I wanted to be a programmer from the age of 8. I noodled around a bit in BASIC, and then taught myself C at around 15 or 16. I was easily into my 20s before I could even reasonably claim that I understood C.
I've turned 40 this year and even though I've written a lot of code in the last 30 years, I still don't really feel like I'm a good programmer, so I tend to always blame myself before the libraries or the compiler or the daemons or the hardware.