I erased all of my cronjobs by accident due to a simple typo.
When working with cron jobs, the command
crontab -e is used to edit your
crontab. This command is one letter off from
crontab -r, which erases your
cron jobs without any confirmation prompt. On a QWERTY keyboard,
r keys are adjacent, which makes it especially easy to type the
wrong one by accident. I accidentally typed the wrong thing, and
*poof*, my cronjobs disappeared.