Here's a true story from when I carried a pager back in the day....
I was out of the office all day and arrived at my last appointment about 4pm. As I walked in, the guy I was due to see was walking out- he'd been called to one of his clients and couldn't see me. He told me he had phoned my office to try prevent me driving to his place, and had asked our secretary to try to get hold of me. At that point I doubled-checked that my pager was on, which it was.
Next morning I asked the secretary if the guy had phoned?- yes she said.
And did he ask you to try get a message to me?- indeed he had.
So... why didn't you page me?
(Bear in mind, readers, that this is a True Story..... Here comes the punchline.....)
I couldn't, she replied..... I didn't know where you were.