Tomori is now 18 months into his move from Chelsea.
He told The Times: "A lot of people didn't believe we were really going to do it and win the title. For us in the changing room to have that relief and joy, proving people wrong and that we were a good team, was sweet for all of us.
“It was just crazy. The celebrations were like nothing I've ever seen before. So many people. It was like a three, four, five kilometre drag of fans, but it took hours on the bus. Stopping at all the lights.
“Obviously I've seen the fans down in Milan, but to see everyone in the streets like that for the whole afternoon, I can't really describe it, just mad."
Tomori continued: "I'm enjoying it and I'm really happy. When I went abroad, there was talk around English players doing this or that, but I've just tried to embrace it as much as I could.
“When I got there everyone was so helpful and helped me settle in. That's helped me to adjust and I want to keep building and improving as a player. Hopefully we can build on what we've done and go on to win more."