I first read about Srinivasa Ramanujan in 8th grade. Back then, I only knew the popular story-that he mostly learned mathematics from a single book containing around 5,000 theorems and then went on to derive many new properties and conjectures, some original and some rediscoveries.
Now I'm in 12th grade, and after actually trying to learn the mathematics behind his work, I've reached a point where I finally understand some of what he really accomplished. He independently rediscovered large parts of the theory of infinite series, zeta function, rediscovered ideas that traced back to Euler's work on series, and much more-all when he was around 16-18 years old.
The more advanced mathematics I learn, the more unbelievable his achievements seem. It's one thing to hear "he was a genius," but it's another to realize what he was actually rediscovering and creating with such limited formal training and resources.
People often say Ramanujan was one of the greatest mathematicians ever, but I still feel the sheer magnitude of what he achieved at such a young age is difficult to fully appreciate unless you've tried learning higher mathematics yourself. The deeper I go into math, the more extraordinary his work becomes