Your portfolio is in double trouble

Portfolio
Portfolio

You're a wise old owl, aren't you? You wouldn't do anything daft like, say, investing in the same stock twice without even realising it? Or maybe three or four times. Or even five or six.

I bet you have. I bet you've doubled up all over your portfolio, and are only dimly aware of what you've done. Why did you do it? What were you thinking of?

For that matter, what was I thinking of?