I wouldn't start to think of someone as a real developer unless they've at least designed & written something of at least 10K LOC or so of complexity from scratch a few times. At least, you're not going to be able to understand these lessons and characterizations of programming in the large unless you do have at least that level of experience.

The larger and more varied projects that you have designed from scratch, the more you start to understand what programming/designing is really about.