If you had these books plus maybe one more about assembly programming you knew pretty much everything there was to know about the C-64. No stacks, frameworks, abstractions, etc, etc. There's a part of me that is really nostalgic for this era of programming.
On the other hand, with the C-64 I only ever got so far. I was really isolated back then. I only had one other programmer friend and when he moved away I had nobody to share my enthusiasm with, and I hit some roadblocks with the programs I was trying to write, and it just kinda fizzled away until the Web and higher-level languages made things easier and forums and search engines let me connect with people.