After the announcement came from Egyptian Vice President Omar Suleiman that President Hosni Mubarak had stepped down, the news hit the enormous mobs of people in and around Tahrir Square like a rippling wave, crested at the presidential palace, where I was standing.
Right now it's a moment of pure ecstasy. Downtown Cairo has turned into a giant parade. Horns honking, flags waving, motorcyles popping off backfires, families pouring onto the street, people offering us food, every face was lit with unbridled jubilation.
A group of teenagers near us chanted, "Muslim, Christian -- we are one!"
Cars drove past, draped with people hanging out of the windows, perched on the hoods and sitting on the roofs. Others walked in groups. Some broke into dance.
"I used to be ashamed to be Egyptian," one man told us. "Now I am proud."
"Now I can get married," said another young man. "I can have children, and raise them in a beautiful country."
Tonight, they have changed their world. And ours.
This giant crowd, which had been peaceful all day, erupted into cheers and marched the 15 miles from the presidential palace back to Tahrir Square.
I had been with them all afternoon and into the evening after sundown, and it was a solid river of humanity.
Tanks had been stationed at the palace. Just hours ago, the most beautiful scene played out before me. I watched the army tanks based outside of the palace slowly, but gracefully, turn their turrets away from the crowd. A soldier in one of the tanks took a flag and started waving it above his head.
The crowd went wild. Soldiers and demonstrators alike were waving and cheering together.
For many Egyptians, the fear is gone. The streets now belong to them. All of Egypt has become Tahrir Square.
Up until now, everyone we talked to stood firm on the fact that President Mubarak's departure from Cairo was not enough. "The whole regime must go," they told me. They all had a very strong sense they needed to finish what they had started.
They wanted to get that democratic self-government, which they achieved on their own, and that is where, in part, this source of unbelievable joy. It's not just the lifting the heavy hand of President Mubarak and the one-man rule for 30 years, but something about themselves.
They have changed not only the politics and government of this country, they changed not only the politics of this region, they changed themselves, and they know it, and that is the source of the joy I witnessed tonight.
Before the announcement, Cairo was calm. The streets surrounding the presidential palace were clogged with mobs of people, their mood intense, but celebratory and peaceful.
A young man, whose brother apparently was killed during this revolution, had tried to crawl through the coiled concertina wire, in tears. Soldiers nearby gently but firmly told him to turn back. Friends helped pull him back out without serious injury.
In the square, we have seen this collective commitment to non-violence. On Monday, a young man was identified as a Mubarak supporter. Dozens of people started hustling him--rapidly and roughly--out of the square.
Upon seeing this, hundreds of people started to chant, "Peaceful! Peaceful!"
Today, there are no signs of pro-Mubarak demonstrators within the crowds. They would be outnumbered.