That's not a nightmare. Somebody else caused it, and you aren't to blame. It's not the code that causes the nightmare, it's the result of the code. Say, a live

That's not a nightmare. Somebody else caused it, and you aren't to blame. It's not the code that causes the nightmare, it's the result of the code. Say, a live production system, where something went wrong due to your coding, causing a great irreversible loss. You realize it the moment it happened, and you can't do anything about it. Closest I got: data inconsistencies in a +5-year old, live core production database of a large company, caused by a coding error. You don't know where it is wrong, you don't have means to fix it (it was wrong from the start), you do know how much was lost because of it. Only 'good' thing was that it wasn't my fault.