i had to add something to the PATH environment variable on Windows and i got the first few attempts wrong, and in the end had to look up how to do it... my pride... a thing my twenty-years-younger self could do, but not me... all these batch commands lost, like tears in rain...

it's not really that surprising however, over time

export PATH=$PATH:/foo/bar

would naturally supplant

set PATH=%PATH%;C:\foo\bar

simply because the former has vastly more day-to-day relevance to my life now; the last time i did the latter, it was on MS-DOS

i'm having a bit of a berenstain bears effect with believing that %variable% was surely never how MS-DOS did variable substitution (surely it's some newfangled Windows NT thing?!), but here it is in the MS-DOS 5.0 manual!

https://archive.org/details/bitsavers_microsoftm5.0UsersGuideandReference1991_25077359/page/559/mode/2up

microsoft :: msdos 5 :: Microsoft - MS-DOS 5.0 Users Guide and Reference 1991 : Free Download, Borrow, and Streaming : Internet Archive

From the bitsavers.org collection, a scanned-in computer-related document.microsoft :: msdos 5 :: Microsoft - MS-DOS 5.0 Users Guide and Reference 1991

Internet Archive
one of my whimsical life regrets is that, as a kid, i understood that batch was a programming language, but i couldn't figure out how to write anything useful with it, because i didn't know where to look for documentation. imagine, imagine, i could've been a batch programmer!
i suppose batch files were always far more limited in what they could do than even the most primitive unix environment, though? i'm not sure if you can even do arithmetic
@hikari
They were! There was a plethora of different "batch extenders" that allowed you to do more, one of the most popular came with Norton Utilities. It even allowed you to make some TUI things — display dialog windows with buttons and other such things.