Imagine that the code you've written today would be running on a critical life support system. Would it work flawlessly or hit a "setOxigenLevel is undefined" error and kill you?
How much would you trust the code you've written today?
I wouldn't trust my code for something it wasn't designed to do i.e. operate a critical life support system. As they say, "Price, Quality, Speed: pick two." Perfect code is expensive and isn't worth it to the client.
I am working on critical medical code. I don't necessarily trust my code more that any other places where I used to work, but I trust the overall organization with proper QA, testing, robustness tests, HW tests, etc.
It is not like I could write some code and it would run tomorrow on a real patient.