Opportunity's Knock

I had an opportunity and missed it and it came out in poem form.

How could I miss him?
He knocked.
I didn't answer.
I thought he was a salesman,
a gimmick.
But I didn't see.
I peeked through the window
and only caught a glimpse.
I should have opened the door
and greeted him,
but I didn't,
didn't take the risk.
he's gone now.
I'd be surprised if he came again.
Maybe I wouldn't hide?
Maybe I'd shake his hand
and welcome him?