In other words, if you're planning on calling him while he's overseas on official business, it better be good.
Just how high a threshold?
When the Nobel Prize Foundation in Stockholm called, Südhof almost hung up.
The caller told Südhof he'd been named this year's Nobel Prize winner for Physiology and Science - the kind of news that usually gets peoples' attention.
“Are you serious?” he told a member of the foundation, according to a transcript of the call released by the foundation's official website.
It was no joke.
Südhof shares the award with two others who have Stanford ties.
Kornberg is a former Nobel Prize in Physiology or Medicine winner, too.
The Stanford neuroscience threesome were honored "for their discoveries of machinery regulating vesicle traffic, a major transport system in our cells."
Rothman is now a professor at Yale University, and Schekman is a professor at UC-Berkeley.
The three will share the approximately $1.2 million, with about $413,600 going to each.
Südhof was in the remote town of Baeza in Spain attending a conference and giving a lecture when he received the call.
"I'm absolutely surprised," he said, according to the report. "Every scientist dreams of this. I didn't realize there was chance I would be awarded the prize. I am stunned and really happy to share the prize with James Rothman and Randy Schekman."
Südhof's group was recognized for exploring how neurons in the brain communicate across synapses.
Südhof in 2009 published research documenting how a gene implicated in autism and schizophrenia alters mice's synapses and produces behavioral changes mirroring neuropsychiatric disorders in humans.
"The brain works by neurons communicating via synapses," Südhof said Monday morning in a telephone interview with Stanford's website.
like to understand how synapse communication leads to learning on a
larger scale. How are the specific connections established? How do
they form? And what happens in schizophrenia and autism when these
connections are compromised?"