I remember watching the launches of Mercury and Gemini missions as a kid and I'll never forget the count down to liftoff. My heart would just pound as the clock ticked down. When it reached t-minus 20 seconds or so it was exciting as the PA guy clicked off the "goes" from the checklists and counted down the seconds. When the rocket fired and it lifted off it was a pure rush of adrenaline for me.
It's funny. I never worried about the thing blowing up or crashing. I was always worried about delays. There were numerous launches scrubbed with only a few seconds remaining. I remember one Gemini launch where the Titan II rocket fired and it shut off right before lift off!
In retrospect, had I known how really dangerous those missions were, I would have been terrified!
Oh man I loved the space program! Actually, I still do to this day.