This is basically the paradox of the heap. Adding one grain of sand doesn't turn a non-heap into a heap of sand, so there's no point at which you've added enoug

This is basically the paradox of the heap. Adding one grain of sand doesn't turn a non-heap into a heap of sand, so there's no point at which you've added enough sand for there to be a heap. Yet if you add enough sand, you clearly have a heap at some point. You can always add more sand and make a bigger heap, but that doesn't negate the fact that you have a heap. The fact that you can't clearly delineate the point where you've learned to code doesn't mean that can't have learned how to code, and the fact that you can get better at coding doesn't mean you haven't learned to code yet.