Katherine Grainger probably has one chance left to win Olympic gold.
At 35, the Scot has been our strongest female rower for a number of years but has finished with Olympic silver on three successive occasions.
Now she must deal with the pressure, frustration and build-up of trying for gold a fourth time in front of a home crowd.
This time around, alongside Anna Watkins in the women's double scull, she has a fantastic chance and nothing would make me happier than if she wins at the London 2012 regatta at Eton-Dorney.
This year, Watkins ended Grainger's run of nine successive victories in annual British selection trials, which shows Katherine is now rowing with somebody at the same level as herself.
Last year the two of them were head and shoulders above anybody else, going unbeaten in the double scull on their way to the world title in Karapiro and being voted world female crew of the year.
Watkins has had some injury trouble so far this season but the duo are back in action this weekend at the World Cup regatta in Lucerne, the last big event before the World Championships in Slovenia at the start of September.
There is a similarity in the dynamic between Grainger and Watkins to the way Matthew Pinsent and I used to work together.
They are two very easy-going people when you meet them but they have a competitive rivalry once in the boat, trying to beat the rest of the world.
When she began her international career back before the Sydney 2000 Games, Grainger was not the star - she was the upcoming athlete in the women's quadruple scull.
Since then she has worked to get where she is and has been so consistent in her performance, summer and winter. She has a great attitude, loves the sport and, when you've got all those attributes, it normally pays off.
But success always hinges on who your opponents are at the time.
That is summed up by the case of Pete Reed and Andy Hodge, the British men's pair.
They are our best men in that boat but, to date, they have not beaten New Zealand's Hamish Bond and Eric Murray in 12 attempts.
At Lucerne this weekend they will try to prove a point for a 13th time. I would be surprised if they win, especially given the efforts they put in to win at Henley last weekend. That may tell in the heats and semi-finals, even if they are back up to speed for the final.
Grainger and Watkins have to expect their opponents to begin closing the gap they have opened up, and this weekend will show whether they have begun to do that. Countries like China, especially, have a different way of organising their teams.
You can win all the World Championships in between each Olympics - and Katherine has five world golds now, after winning her first world medal in 1997 - but it doesn't matter; world titles are stepping stones to Olympic gold.
When I won my first Olympic gold medal in 1984, Richard Burnell - who won rowing gold for Britain at the 1948 Games in London - told me: "You're the world champion for one year, but you're an Olympic champion for life."
That sums up the difference, even though you are racing exactly the same people.
When you come to the big one, suddenly you want to trade in all those other wins to guarantee the one you really want. Unfortunately, it doesn't work that way.
Grainger must embrace the pressure she will feel. The bigger the event, the more excited you should be, the better the performance that should come out of it.
Both she and Watkins are experienced athletes and Grainger, being on the scene as long as she has, knows she is capable. Her opponents also know she is capable.
Now she must go out there and show it.
Sir Steve Redgrave was talking to BBC Sport's Ollie Williams.