I have totally experienced this. I've done TDD nearly exclusively for 4 years now, and I've learned a lot of bad patterns, and a lot of good patterns. Now, if I

I have totally experienced this. I've done TDD nearly exclusively for 4 years now, and I've learned a lot of bad patterns, and a lot of good patterns. Now, if I ever just play around without tests, I find myself using the same patterns as I would with TDD and the code is well structured anyways. I still end up thinking to myself that I will need to test this in the future, so I structure it to be testable because of my developed thought patterns.