Really?
Is that why you've got all that junk in your garage? All those little toys and baubles and sundry, you got that because it was better to have it so you wouldn't need it?
Okay, I can see where sometimes that's good advice. It might rain today, so take an umbrella. Better to have it and not need it than need it and not have it. The power might go out so you can't get in through the garage door, so you'd better bring your house key on your walk. The Russians might develop nuclear weapons, so we'd better develop some too.
But it doesn't work for everything. For example: