Professor Peter Higgs only found out he had won the Nobel Prize for Physics when a former neighbour congratulated him on the news, he said Friday.
The British scientist and his Belgian colleague Francois Englert were jointly awarded the prize on Tuesday for their work on the Higgs Boson particle.
But the 84-year-old said the first he heard of it was when a woman stopped to congratulate him in the street.
The former neighbour had got out of her car as he was returning from lunch in Edinburgh.
"She congratulated me on the news and I said 'oh, what news?'," he told a press conference at the University of Edinburgh, where he is an emeritus professor.
"She told me her daughter phoned from London to alert her to the fact I had got this prize.
"I heard more about it obviously when I got home and started reading the messages."
He said he enjoyed a small celebration on Thursday evening but the main event would be with his family on Friday night.
"There was a celebration, a group of us last night," he said.
"That was certainly a start and I shall be celebrating with my family with the help of a bottle or two of champagne early this evening. It hasn't been possible to get us all together before that."
He added: "How do I feel? Well, obviously I'm delighted and rather relieved in a sense that it's all over. It's been a long time coming."
Higgs and Englert were honoured for theorising a particle -- discovered last year after an tortuous quest -- that explains why the Universe has substance.