Anders -- good for you.
That said, as one of those 'grey beards,' can I recommend that you stop, and go to a technical library or bookstore and find yourself a copy of Rob and Brian's wonderful book: "The Unix Programming Environment" (a.k.a "UPE" or ISBN 0-13-937699-2) then do the exercises. That book is still relevant today - a little secret, I give a copy of it and "Advanced Programming in the Unix Environment" (a.k.a. "APUE") to all my new engineers - even though they are all using 'Linux' for their work. To those that object at first, I remind them, Linux is just the current and most popular implementation of the ideas from Ken, Dennis, Doug, and friends and I'm sure they will learn something from the time invested[1].
FWIW: Besides learning ed (which will help you unlock some of the mysteries of other UNIX tools like grep and sed), take a shot at looking at the introduction to nroff/troff (as has been discussed here - not to restart a war). Learning to use a 'document compiler' like the troff family is never a bad investment.
Have fun,
Clem
1.] BTW I have yet had a young engineer that actually did try the exercises not come back and say something like "Wow, I never knew ...." I don't gloat, but I smile inside, know that I just made them a more effective for our team. If they ask, I point out I had been using UNIX and hacking on the kernel most every day for at least 10 years when it first appeared in the early 80's (84/85 I think), and I learned a few tricks when I read it.
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