Cliche incoming: You never stop learning. :P
I think you're asking about how long it took to begin writing good code. I really had a rough start when I was in college, thinks wouldn't work I wanted them to work - but that was mainly due to my lack of understanding of the concepts and let's face it JavaScript is not exactly kind to new comers. I built some stupid chrome extensions initially, they're still live and the poor reviews are a testament to the crappy code I used to write 6 or 7 years ago.
Then, in my final semester of college (2014 January), I had to build APIs during my internship. I also had the incentive of a full time job if I did well (happy to say I did :D). So, the pressure to ship production level code really did get me going and that's when I understood or rather began understanding how to build software. Of course, it's a perpetual process.