I, too, have had a similar experience. About a year ago I rode the jumpseat in a fairly new A330 into YYZ. The experience was a great thrill - I was able to stay in the cockpit for landing.
About two months later I received a letter from the captain, with similar wording.
On another note, I also had the pleasure of riding in the cockpit a while back with Captain Dennis Giguere on a B747-400 from FRA-YYZ. While I didn't get a letter, it was still an enjoyable experience.
Even though most visitors to the cockpit are usually wide-eyed children, I am still in awe of the technology of flight and I always enjoy riding up front when I can.
(By the way, I think Capt. Giguere is now a VP.)