If you're writing code professionally, then you're not in college anymore and your programs aren't simple things that run from the start of main() through to the end and then exit.

If you're providing a service that needs to keep running, you need a strategy for handling unexpected errors. It can be as simple as "fail the request" or "reboot the system", or more complicated. But you need to consider system requirements and the recovery strategy for meeting them when you're writing your code.

Long, long ago I worked with some engineers who thought it was just fine that our big piece of (prototype) telecom equipment took half an hour to boot because of poor choices on their part. Target availability for the device was 5 9s, which is 5 minutes of downtime per year. They didn't seem to realize the contradiction.