I can't remember where I picked it up from, but nowadays I try to be mindful of when things are "accidentally" repeated and when they are "necessarily" repeated. Abstractions that encapsulate the latter tend to be a good idea regardless of how many times you've repeated a piece of code in practice.
Exactly, but distinguishing the two that requires an excellent understanding of the problem space, and can’t at all be figured out in the solution space (i.e., by only looking at the code). But less experienced people only look at the code. In theory, a thousand repetitions would be fine if each one encodes an independent bit of information in the problem space.
