[TUHS] regex early discussions

Hi All, I was wondering, what were the best early sources of information for regexes and why did folks need to know them to use unix? In my recent explorations, I have needed to have a better understanding of them, so I'm digging in... awk's my most recent thing and it's deeply associated with them, so here we are. I went to the bookshelf to find something appropriate and as usual, I've traced to primary sources to some extent. I started with Mastering Regular Expressions by Friedl, and I won't knock it (it's one of the bestsellers in our field), but it's much to long for my personal taste and it's not quite as systematic as I would like (the author himself notes that his interests are less technical than authors preceding him on the subject). So, back to the shelves... Bourne's, The Unix Environment, and Kernighan & Pike's, The Unix Programming Evironment both talk about them in the context of grep, ed, sed, and awk. Going further back, the Unix Programmer's Manual v7 - ed, grep, sed, awk... After digging around it seems like folks needed regexes for ed, grep, sed and awk... and any other utility that leveraged the wonderful nature of these handy expressions. Fine. Where did folks go learn them? Was there a particularly good (succinct and accurate) source of information that folks kept handy? I'm imagining (based on what I've seen) that someone might cut out the ed discussion or the grep pages of the manual and tape them to their monitors, but maybe I'm stooopid and they didn't need no stinkin' memory device for regexes - surely they're intuitive enough that even a simpleton could pick them up after seeing a few examples... but if that were really the case, Friedl's book would have been a flop and it wasn't :). So seriously, if you remember that far back - what was the definitive source of your regex knowledge and what were the first motivators for learning them? Thanks, Will