I have mkcd exactly ( I wonder how many of us do, it's so obvious)

I have almost the same, but differently named with scratch(day), copy(xc), markdown quote(blockquote), murder, waitfor, tryna, etc.

I used to use telegram-send with a custom notification sounnd a lot for notifications from long-running scripts if I walked away from the laptop.

I used to have one called timespeak that would speak the time to me every hour or half hour.

I have go_clone that clones a repo into GOPATH which I use for organising even non-go projects long after putting go projects in GOPATH stopped being needed.

I liked writing one-offs, and I don't think it's premature optimization because I kept getting faster at it.