@hyc cosigned! It seems like pure tedium, but it's actually very valuable to type stuff in out of a manual, because the boredom drives you to think about what you're typing, and gives you practice debugging simple syntax problems with a known-good reference program.
I think a (solvable) problem today is that back in the day, hardware platforms just did more for you. As someone who got into computers post-2000 originally, it was actually mindblowing to get into retro stuff and discover "oh the hardware would render text for you. And sprites. And if you wanted to know the joystick position you'd just read this memory location." You can do advanced stuff close to the metal when this is your metal. #uxn is a good modern counterpart in a lot of ways.
One of the damaging ways software "ate the world" (Andreesennnn!) is that these features moved upwards for portability, and now you need a lot of software between you and the anemic hardware.