My dad took me when I was 13. We had just moved to WA and was living in a very rural area. We were pretty poor so didn't have satellite and TV reception was garbage, so I really knew nothing about the movie going into it.
The opening scene was pretty exciting, but you were intentionally left in the dark on what was in the cage. I remember after that scene being kind of board as a kid waiting for something good to happen.
When they showed off the dinos and music score came crashing in, I was absolutely blown away. It's imprinted on me as one of the most memorable movie moments of my life time. I knew the move had dinos but because I hadn't seen any trailers I was fully expecting claymation and poor computer effects from the time.