Does one have to be born with extraordinary abilities to become a “Gadol baTorah”?
Absolutely not! The biggest requirement to be a gadol batorah, is to know how to learn in a way that will make something out of yourself. When a person learns gemara and he wants to take it easy and to deceive himself, and he goes smoothly, skips smoothly over the surface like a skater – then he won’t get anywhere.
When a person makes the effort to try to understand and he talks over to himself, again and again, and again and again, with chazara, he finishes the perek, he talks over the whole perek again and again. That person is guaranteed he’ll become a Gadol baTorah!
Of course, like they said on the Vilno Gaon, “Vil nor, vestu zein ah Gaon”. You have to want to be a gaon, you have to work on it. But the way to work on it is to learn the proper way.
If you have chaverim, you can discuss things, pilpul chaverim, that’s very good. But the most important thing, spend time talking over to yourself aloud what you learn and thinking it through. Think it through. You’ll be amazed!
And I would suggest having a pinkas on every masichta. For Gittin separately, Kiddushin separately, Bava Kamma separately, and write down your notes. Every time you go by, you’ll add to those notes, and some day you’ll have enough to say shiurim! And when you apply for a job in a Yeshiva, and the menahel will say “Zug eppes iber”, you’ll say from your notes something, and you’re already established as a mechanech in a good mesivta class.
So make it your business to talk over whatever you learn in a loud voice to yourself, again and again, until you understand it thoroughly. And then you’ll see there’s so much that you don’t understand – that’s the beginning of Lomdus. When you start asking kashas on yourself, that’s a sign that you’re succeeding in learning!