Struggling with injuries since Vancouver, the American has never been on the podium in a World Cup race and his inclusion in the Olympic team was far from a formality with his funding cut off due to inconsistent performances.
"There have been times where I've had to evaluate whether this is really what I want to do, even as recently as yesterday," Weibrecht, who started 29th, told reporters after the race, adding that he had been unhappy with his late starting number.
"I try not to focus on results but I really needed a result to remind me that I'm capable of this and that I belong here."
His team mate Bode Miller led the race until Kjetil Jansrud beat his time. Weibrecht's late charge came within 0.3 seconds of the Norwegian and was enough to bump Miller into third place and a tie for bronze with Canadian Jan Hudec.
Despite Weibrecht's own doubts, his coach and team mates were not surprised by his display, with U.S. men's coach Sasha Rearick saying he had always rated the 28-year-old.
"He's got mad skills...I'm so proud of the team, of Andrew. ... I haven't seen him out of the cage in a long time," Rearick said.
"The name is from when... a coach from another team said Andrew looked like a wombat and I just said 'let the wombat out of the cage'," he added.
Weibrecht, who has had several surgeries since Vancouver, skied out of the slalom leg of the super-combined race, his only other appearance in Sochi, and started the super-G when the favourites had all long gone down the mountain.
"I was probably one of the few guys who wasn't surprised," said Miller of his team mate. "I ski with Andrew a lot and he's so much better than his results show on the World Cup. He's one of the guys who could consistently win."
Weibrecht beating Miller's time bore a certain irony as Miller radioed tips up the hill ahead of Weibrecht's start and Weibrecht raced on a pair of Miller's skis.
"He's just an unbelievable talent," said Miller, adding the course had likely slowed by seven tenths of a second by the time Weibrecht started.
"To ski through the toughest conditions of anyone in the top 30 and come through on top is just incredible."
Weibrecht, also dubbed "the Warhorse" for his reckless skiing style, said he knew he had skied fast.
"It's unbelievable. I came down and knew I skied well. I knew I had a good run," said Weibrecht, whose family did not join him in Russia because they were concerned over security.
"I came through the finish and appreciated my run. Then I took a couple of seconds and looked at the time, I saw two and looked away. I looked again and was like, 'You've got to be kidding me'."
A silver medal is likely to put Weibrecht's doubts to a rest for a while.
"This is probably the most emotional day of ski racing I've ever had," the short, blond skier said.
"All the issues and troubles I've had, to come and have a really strong result like this, it reminds me that all the work that I did to come back from the injuries, just dealing through all the hard times, that' s all worth it. It all makes sense."