Back in the mid 80s, I was working with a fellow student to develop a major computer project. We had worked on this for two months and did not do any backup. One Sunday, we really messed up the program and could not retrieve the file at all. Since the system was backed up on Saturday mornings, we figured that we could get the IT department to retrieve what we had on Friday night.
Monday morning we went in to see what could be done. They look into the tape for the recent system backup and found the tape to be blank! The system backup contained all grades, salaries, student and faculty accounts, you name it it is supposed to be on the tape.
They looked at the tape from the previous week. It was also blank and so were the tapes from the previous 10 weeks! No one had been checking them. It turned out to be a faulty recorder. We had notes enough from printouts and evidence from a tape weeks earlier to be awarded a grade and the IT department learned a serious lesson.
So, yes, check your backups. Many people are backing up their home systems but practically no one is checking the quality or extent of what is actually being backed up.