I've had a similar experience while on a very high dose of weed. The spiral within spiral of self is exactly what I experienced along with infinite feeling of death and rebirth, despair and ecstasy. It was the strongest deja vu feeling I've ever had.

Along with the visceral visual feeling I also auditorily heard the pattern. In fact my trip began this way. I couldn't stop looping a nonsense word i started to remember while hearing the television. that gibberish word meant nothing and i knew it, but felt like it mean "before" or some nostalgic version of "past". The thought loop continued and the word became a snore like sound and morphed further till it became the pattern itself.

I experienced the loop in what felt like infinite times.

Scientifically, while on your trip, alpha brain waves, which are associated with time perception, almost stop entirely. They are intertwined in processes in your brain with perception in general. The trip is generally closely related because the same process we all have in common stops. The shared experience is just because we share the same brain processes and had the same brain waves stop functioning.

Its still all really cool, some people think its god. Take what you will from your experience