The place was heaving. The audience was a sell-out, maybe 3000-strong. Families, students, scientists and fans.
Everyone there had chosen to miss a dramatic Lions rugby test for an evening with an 83-year-old and a handful of photographic slides.
I sat in the bleachers by a bookish young teenager, who whipped out a paperback to pass the minutes in the intermission.
Jane Goodall was fantastic. The audience clung to her stories as she guided us through her incredible life.
She plotted how, from World War II London, she escaped Britain for the mighty forests of Tanzania and Congo. She told her audience about the defining moment of her scientific career: when she became the first person to witness a chimpanzee fashioning a tool in the wild.
It was one of those evenings where, despite missing the rugby, it was impossible not to feel good.
Goodall is an especially gifted communicator - she swept us up in her message and her stories. She made poignant points about conservation and politics, and the impact that various social problems have had on her beloved chimpanzees.
She spoke succinctly and effectively on the risks of climate change but left her audience optimistic about mankind's potential to slow the rot.
Goodall's final anecdote of the night concerned an orphaned chimpanzee whose life was saved by her foundation. Against all odds, the rescued chimp has recently given birth to a healthy little baby.
In her punchline, Goodall revealed the baby chimpanzee's name: "Hope".
Everyone in the auditorium rose to their feet and sustained their applause. We filed out, enlightened, inspired and not for a moment regretting missing the rugby.
These people of course, were riding a wave of love, optimism and hope. Conservationists, vegetarians and recyclers: a mass of people united by the profound respect for all living things.
In the carpark, the queue of cars stretched for hundreds of metres. For 15 or 20 minutes, not one sod would let me in. We're doomed.
• Jack Tame is on NewstalkZB Saturdays, 9am-noon.