Errors, errors, errors. Errors are everywhere. I recall a joke I had made on social media a few years ago where I said
I am a good enough programmer, don’t expect errors in every program I write B)
This was a remark on the (in)famous practical record books I had during my undergrad, where I had to code a simple program that would probably exemplify linked lists, arrays, and what not, and there I’d have to write an answer or provide an example of an output. It also had sections for “errors encountered”.