We listen to SirrusXM satellite radio and during November and December they play holiday music. After several songs, a brief Christmas program or movie excerpt interlude is played. One excerpt had just a toy steam train whistle. Yep I said to wife, that's a postwar Lionel steam engine tender air whistle. Having only heard my MTH electronic whistles and horns she said "And you know this how?"
Where upon we went to the layout and placed my (first Christmas) Lionel 2055 steamer on the rails and proceeded to blow the whistle just like the radio segment. She, with the musicians ear, agreed it sounded exactly like the excerpt.
Some memories become so ingrained, like riding a bicycle, you just never forget.