Why do you say Aha?

Neville: "I've never worked abroad before. I've been abroad, like. Me and Brenda went in Menorca, twice."
Oz: "Twice, why twice?"
Neville: "We liked it the first time."
Oz: "Whereabouts is it, Menorca?"
Neville: "I'm not really sure, we flew non-stop from Newcastle."

In Auf Wiedersehen, Pet

By Bean & Crumpet