Dumbo. The movie was originally released in '41 but my parents took me in '55. I remember the cavernous theater and the size of the characters on the screen. It was a huge deal for me...

And let the record show that I suffered about a 3 day meltdown after the movie. Mom says I sat on my stool and cried softly until Wednesday after a Sunday show. Also let the record show that the theater was a bit over 100 miles from home, a really major undertaking.