Ah, I see what you mean. Apologies, I didn't mean to digress from the spirit of your comment, I suppose it just varies with experience: of the things mentioned, including web frameworks, I _did_ hear of the history of how people have done databases, but other than that GNU tools are just things I used to get the work done, and I learned git through open source. (Though I think it would make a great 'stuff you've learned put into practice' talk: diff algorithms, data structures, etc.)