Britain's top 400m runner Tim Benjamin is in the business of answering his critics this season.
Born: 2/05/1982, Cardiff
Honours: AAAs champion (2002, 2004, 2005), World Youth Gold (1999), European Junior gold (2001), Silver (1999 (200m) & 2001), Commonwealth 4x400m silver (2002), World Indoor 4x400m bronze
Personal best: 44.75
Coach: Tony Lester
Best friends in track & field: Girlfriend Natalie Lewis and Marlon Devonish
The 23-year-old Welshman went some way to doing that at last month's London Grand Prix, breaking 45 seconds to defeat Olympic champion Jeremy Wariner in a major upset.
And now he he is hoping for success on a bigger stage, when his event kicks off at the World Athletics Championships in Helskinki on Tuesday.
Benjamin watched the replay of the London race for the first time without so much as a glimmer of a smile - he knows it will take more than that one victory at Crystal Palace to set the record straight.
"Over my career, I've heard people say 'he's not reproduced what he did as a junior' and I get frustrated and angry," Benjamin told BBC Sport.
"People don't give athletes time to develop or to have an injury-free year.
"So I built up a list of what people said in my head and used that to spur me on.
"I was happy to beat Wariner and to record a personal best (44.75) but that race is over now and it's on to the next one."
This is the new and improved Tim Benjamin - full of fighting talk and in good enough shape to back up the bravado with world-class performances on the track.
His rise, after a glittering junior career, has been stalled by a series of injuries.
This season seemed to be no different when he spent most of March in hospital after a back injection left him with severe headaches and a freak gym accident damaged his knee.
But Benjamin returned from injury - and a bout of flu - to win the AAAs crown and then become the eighth fastest man in the world in 2005. So what's changed?
"I've really worked on trying to strengthen my body so I can put it through the training," said Benjamin.
"The training is tougher than the race itself. After some sessions we have to lie down for half an hour because we feel so bad.
"I've also become more relaxed in my approach to racing. I used to get all hyped up and nervous and I couldn't execute the race properly.
"Away from the track, I just try to take my mind off running, although that is very hard."
Benjamin now hopes his focused mental strength can ally with his physical improvements to win him a first individual medal at a major championship.
Benjamin (right) and Wales team-mate Matt Elias after winning Commonwealth relay silver
Junior prizes aside, the Welshman only has a 4x400m Commonwealth silver and World Indoor relay bronze to his name.
The competition for medals in Helsinki will be intense, with Wariner and fellow Americans Darold Williamson and Andrew Rock going for a US one-two-three. Canada's Tyler Christopher is also in the mix.
"I do expect Jeremy and Darold to pull out more in the final because they are big-time competitors," Benjamin said.
"I really would be disappointed if I didn't make the final. I know if I put my mind to it then I can beat most people.
"But I just have to recapture the form I was in at Crystal Palace and run another tactical race.
"What I can't do is to rest on my laurels. If I rest back and think 'great, I'm in 44.7 shape', I'll just go out and run 45.3 again.
"I can celebrate at the end of the season but now is not the time as I have to stay focused for the Worlds."