The noble art of giving things a spin..
I recall working at a site in London - nice shiny location, pretty high value activity.
The usual on day one: handshakes and hello at reception w security guards, wave at camera for badge, badge issued w lanyard
Tuesday I fall out of bed a tad late and rush to get there in time - only to discover on entering the building that my new entry badge is in my other jacket. And the security guards are different, so they haven't seen my face. Bummer.
Oh well, I successfully tailgate instead, and I keep doing that for the next 3 weeks (but now w badge in pocket in case one of the guards finally decides to challenge me - which never happened).
The problem for them: I was securing one of the companies in that building - this accidentally made a nice extra chapter in the report.
They put proper access gates in not long after - it wasn't the only high value company in that building..