Comment by kccqzy

Copy-pasting itself is not bad per se. What's bad is copy-pasting without understanding the why and how.

For LaTeX I also copy-paste a whole lot from older files, but I don't feel bad because (a) I wrote these files before, (b) I know exactly what each line is doing, (c) I understand why each line is needed in the new doc.

I wrote a relatively large amount of TikZ code earlier in my life (basically used it as a substitute for Illustrator) and for this library in particular, I think it just has so much syntax to remember that I cannot keep it all in my brain for ever. So I gladly copy from my old TikZ code.