It's a filthy lie!

Snopes is on the case. Steven Spielberg did not sneak onto the Universal lot and subsequently work his way into the hearts of American audiences.
However, I have it on good authority that about 10 years ago it was incredibly easy to sneak onto the Universal lot, wander around, visit movie sets as they were being built, play random pianos sitting in empty sound stages, stroll past the Psycho house, eat free food and rub elbows with A-list celebrities, and more!
It was also very easy to put a couple of friends in the trunk of your car, park on the back lot, and walk into the theme park unnoticed.
I will never reveal how I came upon this information, nor will I tell how to get two adults into the trunk of a Celica.