I only have an opinion to offer here, right now ;-) so for better or worse, here it is. It covers direct management of others' opinions ( immediately below), managing their effect on ourselves here, and a brief reminder of media attention here.

Managing opinions directly
We can do little about other peoples' opinion of ourselves. Though it's a factor in confidence, I don't think it's often sensible to attempt direct management of opinion for yourself (there goes a whole marketing industry... :o) ) Whatever, my take on that one is:

       Let your achievements speak for themselves.

The implication is that the most you can honestly do to change an opinion is to make the facts available. But it is a time consuming business, and for the most part won't change your scores. I think the only time it's worth 'managing' another's opinion in this context is when someone who really matters just doesn't share your view of 'success'. That can be demoralising, and you can do without that. Under those circumstances, you can either live with it or talk about it honestly. Not much else works.

Managing the effect of opinion
You CAN do something about the way other peoples' opinion affects you. For example:
 Consider how well informed the opinion is; if they don't know everything, the opinion is worth that much less.
 Remember how easy it is to focus on others' failings; 30 wins won't count as much as a recent second place in many eyes.

But on the whole, I don't think it's wise to pay a lot of attention to other people's opinion. You're the only person who really knows what 'success' means to you, and the only outsiders who should influence your performance targets are the people you're trying to beat. And if that's true, their opinion isn't important; only their performance matters.

The media
Finally, one set of opinions to think about in advance. If you get really good at this game, you'll meet the media. This tends to be a difficult experience. Particularly as most of them don't want your life story, they want the first news on the next doping scandal, or the gossip on which of the power lifters is gay.
So if media attention is on the cards, prepare for it in the same way as for any other possible downer; get your coping plan sorted in advance. a) Prepare for unwarranted flak and lousy press readings from journalists with next to no understanding of your sport and an apparently unshakeable belief that placing fourth in the world is a failure. You don't have to listen. b) Make damn' sure your team manager is prepared for it too. c) Take advice from someone who's been there; it'll pay.