Global mutable state is like a rite of passage for devs.
Novices start slapping global variables everywhere because it makes things easy and it works, until it doesn't and some behaviour breaks because... I don't even know what broke it.
On a smaller scale, mutable date handling libraries also provide some memorable WTF debugging moments until one learns (hopefully) that adding 10 days to a date should probably return a new date instance in most cases.
Novices start slapping global variables everywhere because it makes things easy and it works, until it doesn't and some behaviour breaks because... I don't even know what broke it.
On a smaller scale, mutable date handling libraries also provide some memorable WTF debugging moments until one learns (hopefully) that adding 10 days to a date should probably return a new date instance in most cases.