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.

On Mon, Mar 29, 2021 at 11:16 AM Anders Damsgaard <anders@adamsgaard.dk> wrote:
* Larry McVoy <lm@mcvoy.com> [2021-03-29 07:34:49 -0700]:

>I had *.clients.your-server.de crawling mcvoy.com in violation of my
>robots.txt.  For whatever reason, the tty settings (or something)
>made vi not work, I dunno what the deal is, stty -tabs didn't help.
>
>So I had to resort to ed to write and debug the little program below.
>It was surprisingly pleasant, it's probably the first time I've used ed
>for anything real in at least a decade.  My fingers still know it.
>
>+1 for ed.  It's how many decades old and still useful?

I recently learned ed(1) for the first time (I have a unix beard, but it's
not grey yet). I found ed to be very efficient and useful for small fixes,
even on slow connections.  This beginner's tutorial was very helpful
for me: gopher://katolaz.net/0/ed_tutorial.txt

(https mirror for non-gopher clients:
https://adamsgaard.dk/npub/ed_tutorial.txt )