By the time you're 35, you should have successfully done following at least once: 1. rm -rf / on your unix or linux box 2. Reboot production server by mistake 3. Drop CPU/hard disk and damage it permanently 4. Changing firewall rule instantly blocked you out 5. No backup was made/verified ever... 6. Delete source code before actually committing to source control 7. Run a SQL update/delete with wrong where clause