This, exactly this. I've felt the same increase in development velocity; and an equal increase in confidence. I'm able to deliver systems and walk away with 99% confidence that no one is going to come back to me with a problem. And if they do, it's easy enough to write a regression test to prove the problem and then fix it.

I've adopted your same approach. I don't mention testing, but I'll be damned if I'll ever write a piece of code without it.

The light-bulb moment for me was when I realized that testing happens one way or another. Either you're in the console manually setting up and running everything... or you could just write a program (a test) to do the same thing for you. Once I realized that, I never looked back!

I just started learning how to write tests for my APIs. Changed my life! Now when I need to make broad changes I can easily tell what needs to be fixed because my tests cover each end point with multiple success and failure cases. Love it.