[klysm]

Over the years I've come to realize the copy paste has probably been a net negative for me and I almost never do it anymore. If you are doing the copy-paste, then change a couple names to match a different pattern thing by hand, the subtle errors you can get by making a mistake can take forever to catch. In code review it always looks plausible unless the reviewer is _very_ careful. Furthermore, it means you are duplicating code - which is sometimes totally fine - but forcing yourself to not copy-paste makes you consider what the abstraction would be and if it would be worth it not.

In the case where you are copy-pasting out of code you don't really understand. Retyping it gives you time to understand and maybe catch existing bugs in the code you are copying.