Buchanan started the BMX final at her debut Games in London with the nation's hopes on her shoulders, after qualifying fastest.
But the 24-year-old mountain bike and BMX world champion was left shattered and in tears after she missed the start and finished fifth.
Since then she's won two BMX World Cup series and is enjoying cracking form early in the international season, fresh off this week's win at the 2015 series opener in Manchester.
That showing makes an impressive case for qualification in next year's Olympics, and Buchanan says the thought of another shot at a gold medal has been her primary incentive since the moment her London Games ended.
"When I crossed the line in London I knew that I sort of blew it for myself," Buchanan told 2KY's Big Sports Breakfast on Thursday.
"I guess you could say I cracked under that pressure in the final moment.
"I was like, `Damn, I've got to wait four years for the next Olympic Games'.
"And it really spurs me on to basically come in entirely way more prepared than I was for London."
Buchanan said she's under no pretences about the marked increase in international standard this year, but is buoyed by strong results in training as she embarks on next week's BMX National Championships in Brisbane.
"Every race just builds that confidence onto the next," she said.
"So if I can have a good nationals, I'll then be in fighting form coming into Holland (World Cup second round) in two weeks' time.
"A year out from the Rio Olympics the qualification has already started so I'm just focusing on Rio now and qualifying."