I am actually gladdened by reading the posts by others on here mentioning how they did the same thing. I've been kicking myself for decades over a similar thin

I am actually gladdened by reading the posts by others on here mentioning how they did the same thing. I've been kicking myself for decades over a similar thing I did when I was starting out as a programmer. Not as big as some of those here, but back in the late 80's I was a self employed programmer writing DOS apps for local businesses to help them run more efficiently. There was a local martial arts supply shop whose owner was sort of a friend of mine, and he engaged me to write a stock control and hire database for him, which I did. When it came time to implement, he told me that there was a LOT of data to enter, so he would hire a couple of young students of his to sit down for an entire week and key in the data, which was all good. After they had finished, he called me back in to 'go live', and I sat down in front of his server PC and began to check that everything was OK. Normally, it is my habit to take a backup of the entire app directory before working on it, but I think I was going through a break up with my then girlfriend and was a little sleep deprived. I noticed that some temporary indexes had been created during the data entry and I went to quickly delete it (thinking to rebuild all the indexes for best performance), but typed in 'DEL .DAT' instead of 'DEL .KEY'. I still remember that sinking feeling as I sat there looking at the blinking 'C:\>' prompt, knowing I had wiped out all his work. Telling the owner was also one of the hardest things I have done, and I fully expected him to pull down one of the sharp oriental weapons from the wall and take me apart. But he was really cool and understanding about it. He refused my offer to pay for the students to come back in and re-key the data again, which actually made me feel worse, because I knew he wasn't having the easiest time at that point making ends meet in his business. End of the day, we got it all working and he used the system for many, many years. But to this day, I still make a copy of anything I am about to touch, before I work on it.