world-wide DC access
When I left a certain company, back in the beginning of the new millennium, HR had a list of company property they wanted me to return and when they were done with their list I asked them to add a single item to the list:
"Data centre access badges and keys". Just 3 access badges and 7 (or 8) keys opened all global data centres 24/7 and about 95% of all racks.
I got a phone call 2 weeks later by the VP of IT how the hell I amassed so many... Told him: solve lots of critical issues for more than 10 years and people will just tell you: "Keep them for next time you have to perform magic"