One way this is formulated is the "Rule of 3 for Abstractions": One copy of something is YAGNI. You aren't going to need it (an abstraction). Two copies of so

One way this is formulated is the "Rule of 3 for Abstractions": One copy of something is YAGNI. You aren't going to need it (an abstraction). Two copies of something are coincidence. It's fine to copy and paste and leave it that way. Three copies of something are finally a pattern. At least three copies are when you start to really see what sort of abstraction that you need to handle the pattern.