Island in the Sun and perfect pitch

Something interesting occurred today. I looped 3 or 4 times over Monty Alexander's tune "Island in the Sun" while on my way to work (I love it that much). I sat at the piano in the evening --10 hours later-- and started playing. I heard the tune perfectly well in my head, and what else, there was no doubt in my mind what pitch it started on. I checked, it was an E. Then I played Monty again, and sure again, it starts on E.

So I was able to memorize with a good degree of certainty the starting tone of "Island in the Sun" after a 10 hour break.

This reminds me of my teacher who said once: "I know Bb because I played Misty so many times".

Next step, associate E to this tune. I will try again later...