Wasn't there

Sitting on the #75 bus headed east on Lombard, I saw a middle-aged woman get on and make her way down the aisle. Once and awhile she would stop and look suspiciously at certain seats. She sat next to me. Presently, she said, "There are so many invisible passengers on the bus today!"

I looked at her but said nothing. "And they don't pay for their tickets, either!" she added.

"You were lucky to find a seat," I replied.

But I really wanted to ask her how she knew they hadn't paid.

---

"Yesterday upon the stair,
I met a man who wasn't there.
He wasn't there again today.
Oh, how I wish he'd go away."

-- Hughes Mearns. Antigonish 1899