In that case, I think attitude is even more important than aptitude.
There are people who seem to have been born to program. But I think that with perseverance everyone can learn.
If you are steadfast and don't give up at the first opportunity, you will learn faster because the best way to learn (I think) is making mistakes (yes, I'm not crazy... well, maybe a bit XD) and trying to correct them.
And as Eivien said, if you already have programming knowledge the way will be easier.
That was my case. Before I started with RGSS, I already programed in C/C++ and Pascal. So it took me no more than six months (to program a fully functional script, as you said; small editions took me about... 5 minutes? XD)
However, I have been 'RGSS-ing' for two years and a half and I'm still learning. In fact, I'm almost sure that if we ask Trickster, Samo, Moghunter, DerVVulfman, Aleworks, etc they will say this: 'yes, I'm still learning'.
regards from paranoyas