I write Python. While I read the original post and nodded along, nothing changed about how I worked until I started playing with Rust. Seeing a strongly typed language force the constraints and stop stupid errors was when the rationale finally clicked for me. Knowing that this function will never blow-up in an unexpected way changes how you think about problems.

You otherwise get accustomed to some wishy-washy blobs of data that get passed around and find it normal. Maybe you include some ad hoc guard rails here and there, which catches the egregious errors, but there is always some lingering uncertainty. Some string that should have been an int, missing key here, the object which never had the validation check, etc

It is like unit-testing - more-up front work, but I could never go back to a world where I did not get these automated assurances. Sadly, I am a grug-brain which could only feel the lesson from personal experience.