https://www.executiveforum.com/cutting-off-the-ends-of-the-h...
tl;dr nobody in 2 generations knows why they cut the ends off the ham before cooking it, until they talked to grandma, who said her pan was too small
A Unix thing that's been posted to HN for a decade, that's almost literally the same story:
Understanding the bin, sbin, usr/bin , usr/sbin split
https://news.ycombinator.com/item?id=3519952
tl;dr /usr/bin is separate from /bin because someone had a small hard disk once