If I dedicated myself to it right now, really felt it, spent hours and hours on it, and loved it, could I be as talented by 27 or 28 as some of the people who have been playing since they were like 5?
Agreeing with suwahaksaeng – yes, you could become competent, and even fairly good – but *on top* – which I assume you to mean *famous* – not possible. The skills needed, in all their nuanced subtleties, take a LIFETIME to develop- and only if started from the cradle. The oft-quoted "10,000 hours" theory of skill -learning works for many things – but not THIS. If a child were instructed, and practiced, 4 hours a day, 360 days a year for 7 years – then they would reach this between ages 4 and 11. However, the LEARNING modalities and their imprints at this age CANNOT be duplicated if you spent that same amount of time as an adult. All the foreign languages I have studied in school, beginning around age 13 through college level, are NOWHERE as good as the kitchen-table language skills I grew up with in a bilingual home. I do not have a professional vocabulary in that second language – but can carry on lengthy conversation, thinking in that language. After 3 years of HS French and 2 years of college German – I can read and write, and speak SOMEWHAT fluidly – but not like the Polish I learned from birth. No comparison.