Found an absolutely delightful old computer reference book: The ResEdit All-Night Diner by Dave Ciskowski, which is entirely about tampering with pre-existing applications and system files with ResEdit and written in an unnecessary and unhinged metaphor about ordering food at a diner. Such narrow bands of human technology and culture had to intersect to make this artifact possible.

Scans are available for this and a staggering amount of other books at Vintage Apple: https://vintageapple.org/macprogramming/index_year.html

Brand new and very "entertaining" computer issue on my Mac today:

So when you open up a new window in Terminal.app, it runs the standard login utility that among other things displays the last login time while setting you up in a shell, normal Unix-y stuff. After about 5 minutes of uptime, it would start hanging there for about 5 seconds and then just kick to command line without displaying the last login time. The last command would also stop displaying any current or past logins.