Lopez, whose younger sister Diana is also aiming for gold in London and who is coached by his older brother Jean, took gold at the 2000 and 2004 Games and has won five consecutive world championship titles. Still, his bronze in Beijing stings.
"It was a bit of a wake-up call for me. I had won the last three world championships at that moment, the last two Olympic Games," Lopez said. "For me it was just clock-in, clock-out, automatic. And it just woke me up a little bit to see 'hey I can lose' and to appreciate my victories."
That experience prompted him to train even harder and return to the Games with a strong will to win.
"I know what it takes to be on top and I know I've done that. As long as I keep things in perspective, keep focused, I know I'll do a great job," Lopez said.
Diana, who also won bronze at her first Olympics in Beijing, showed the same can-do-attitude.
"I'm 28-years-old but I feel I can rock and roll with anyone who's in front of me. I rock and roll with all my brothers back at home, so there shouldn't be a competitor nearly as strong and talented as them," Diana Lopez said.
Steven, Diana and their brother Mark put their stamp on Beijing when they became the first three siblings to make the same U.S. Olympic team since 1904. This time, Mark did not qualify, losing his place on the squad to Olympic novice Terrence Jennings, 26.
Active in taekwondo since the age of five, 33-year-old Steven gave no indication on Saturday that he intended to quit anytime soon.
"I want to be the best, not just the best for now but for a very long time. A lot of people are able maybe once or twice. I want to do it as many times as possibly can," he said.
Korean martial arts taekwondo hit the headlines in Beijing when Cuban fighter Angel Matos kicked a referee in the face after he was disqualified. Britain's decision to leave out world number one Aaron Cook has also sparked heated debate.
But the sport has moved to become more attractive for laymen with a new scoring system that encourages fighters to attack and try more spectacular head kicks as well as electronic sensors that will help judges determine a score.
The rule change will award points for a head kick even for the slightest touch, whereas previously the kick had to be delivered with significant force.