With Software in particular, I often encounter designs that copy a pattern from another popular piece of software, but without critically thinking about what the pattern is for or if it's even appropriate for their system, or even worse, assuming that because it exists and is popular that it must be good, when in fact it's terrible.

If recreating someone else's creation truly learned us, I believe the world would be a tremendously better place.

I used to run a lunch study group where we took some old crusty load bearing software, read the documentation thoroughly, and then dissected it, reading source and comments and trying to distill what it achieved well separate from what it achieved in spite of itself.

We learned a lot.