Where did they come from?

Today is the Rome TT and it was crazier than ever. Last year the crowds were big but it was insane. I drove through the parking lot to the start of the TT. AS I shut off the engine to the truck there were people standing in front of the truck. I opened the door and there were no less than a couple hundred fans waiting.
The TT went OK by TT standards. But they are always crazy and there is always something to do. Constantly. Trainers, Change chainrings, pull out the awnings (it started to rain). Computer on one guys bike. Computer off the other guys bike. It could theoretically go on forever. But I like busy.
The crowds were so thick and loud that I had a real difficult time even hearing what Juan would say or ask. We almost had to yell at each other to tell them what each of us needed or was doing.
Crowds were cool, supportive and loud. But, where did they all come from so fast?