During the Clinton presidency, he used to do a theater weekend in NYC, and the shows he was going to see were public knowledge, but not the dates and times for security reasons. We had tickets to see Chicago the Saturday night of that weekend, which was summer 1999 and that morning we received a phone call requesting that we come to the theater early for "security reasons". (they had our phone number through the credit card purchase.) It wasn't hard to figure out the reason for the call.
We arrived, went through a magnetometer and the theater was electric. Everyone took their seats (there were obvious Secret Service around and I'm sure some that were not as obvious). After the house went to half lights, Bill and Hillary came in and took their seats in Row L center, a few seats off the aisle to thunderous applause. We were in Row G, left aisle, and at intermission people on their way to the lobby walked up the aisle and the President shook everyone's hand as they went by. Most people were saying something like, "thank you for supporting the theater, Mr. President" and keep walking.
I decided to see if I might be able to get him to respond to conversation, so as I shook his hand I said, "Mr. President, we have something in common." He said, "what's that?" and I replied that both of our daughters were leaving for college that fall for their first years. He said, "where is she going", and I replied "Smith College" and which time he grabbed Hillary, who had gone to Wellesley (a rival school) and said "His daughter is starting Smith this fall." Finally he said, "Well I hope you are looking forward to it more than I am", and that was it, but it was both touching that he was clearly anticipating missing Chelsea and that he was speaking to me father to father.
So that's an experience I doubt I'll ever forget.
CZJ at opening night party for A Little Night Music, Dec 13, 2009.