I always wonder about kids who skip too many grades or who get college degree at 12. Even if they are intellectually there, socially life would be a nightmare. Imagine being a 12 year old which 17 year old peers. I can't imagine the emotional trauma!
I didn't do any IIT coaching and was able to prepare for IIT only for one year in my grade 11. After that I got some major health issue and was harassed by armed bullies in my school, so couldn't study at all in Grade 12. This made me miss Top 200 rank.
But this ended up being a blessing in disguise, because I couldn't get Computer Science at IIT. I have been passionate about computers since I was 8 years old. If I had studied Computer Science as a part of the course curriculum, I might have ended up hating it.
Instead I pursued Computer Science on mine own, based on my interest. I have loved it every single day!
I look forward to my work, versus most of my friends who feel trapped in their jobs!