Entirely agree. DRYing is compression. It serves similar purpose. Like a mathematical equation, it's terse, light, elegant, easy to carry in one's pocket, yet l

Entirely agree. DRYing is compression. It serves similar purpose. Like a mathematical equation, it's terse, light, elegant, easy to carry in one's pocket, yet loaded with meaning. It's not, however, zero cost. At maintenance time, it needs unpacking. DRYing is also not an exact science, nor a hard rule. It's the factorization of a specific idea (at least that's what it should be). When applied, it requires usability and cognitive considerations. That's the delicate trade-off. "Will people coming after me have an easy time figuring this out?" The newbie who comes to an existing code base and proceeds to indiscriminately DRY things up often doesn't realize that the reason they were able to do so in the first place is because, although repetitive, they could understand the original source, often without much effort. That's why repetition is cheaper than the wrong abstraction.