The closest I ever came to truly "going postal":

I was at the Hollywood Post Office submitting the paperwork to rent a P.O. box. I had done my homework online, and I brought two forms of unexpired, government-issued ID, i.e., one California DL and one California ID.

The officious postal clerk demanded more documentation because, even though the DL and ID were different documents with different photos taken on different days, the reference number on both was the same.

I handed over my proof of auto insurance card.

She reviewed it closely and rejected it on the ground that it expired several days earlier.

I explained that sometimes the insurance company sends the new card a week or two late, but that shouldn't matter because (1) I'm obviously me and (2) the Post Office is renting me a P.O. box not a frickin' car.

Not good enough.

So I drove back to Sherman Oaks to retrieve my passport, thinking dark thoughts.

Now I make it a point to avoid that postal clerk.