Backing up is something that could be said a thousand times over.

I truly lost money because I didn't back up my private keys.
Articles, poems, diaries that took dozens of hours to write—once the hard drive failed, they were all gone.
That feeling is even worse than losing money.
Backblaze survey: 54% of people have experienced data loss.
If you don't back up now, the next one will be you.
Simple rule:
Normal files → 2 copies
Important files → 3-5 copies
Distributed across computers, hard drives, email, cloud storage
For truly important data, print a paper copy
Backups only take 1 minute; if lost, it may take dozens of hours to recover, if at all.
Losses will happen.
Backup is the only regret medicine you leave for yourself.