Wales' late defeat by France to end their Six Nations Grand Slam hopes will haunt them for years to come.
They were 30-27 up and in possession when they were caught off their feet and conceded a penalty in the final minute, playing with 13 men, and France took the chance to score.
Wales will still win the title unless France beat Scotland with a bonus point and by a margin of more than 20 points on Friday, but no one thinks about that once you have lost a Grand Slam.
Unfortunately I have been in that scenario far too many times, when the Grand Slam has been on the line and England have lost. There are going to be some sleepless nights for Wales.
I still have flashbacks in my dreams to the moment Wales' Scott Gibbs scored a try in the dying seconds at Wembley to deny England a Grand Slam in 1999.
In years to come, that Welsh side will have flashbacks to coughing up the ball on 80 minutes and letting France have one last opportunity. It will haunt them - it is not a nice feeling at all.
You get reminded of it, you still see it on social media. It absolutely haunts me and will do forever.
'France are so dangerous'
France are creating some unbelievable rugby. Everybody now knows if you want to beat France you have to play a certain way and score tries.
It does not mean they are invincible, but I am convinced we are going to see a significant period of time where France are going to be very dangerous.
All of a sudden the players and coaching staff have bottled the flair that France always used to have, but combined it with the discipline and game management they never had before, and are winning these sorts of games.
Wales had total control but when France lock Paul Willemse was sent off in the 68th minute, it was as if someone pushed the red alert button in the French camp.
They started playing like their lives depended on it. With a 10-point lead for Wales, I did not see France winning it but when they got in the 22 and even before Willemse was sent off, Wales started to give multiple penalties away and lose the referee.
You thought it would go to the wire but Wales would have enough in the locker. After sealing what seemed like an unlikely win, France look so dangerous now.
'A sensational Six Nations'
During the 2020 Autumn Nations Cup, I said rugby needed a change to avoid the turgid play we were seeing.
And in this Six Nations, most of the games have been absolutely fantastic from beginning to end. There has been a lot of drama.
You might not like it because your team does not win but more often than not the games have been sensational.
Given the circumstances we are all in, rugby desperately needed the shop window of the Six Nations to be right up there. I cannot remember a Six Nations like this.
'England's fifth-place finish not acceptable'
England won the Six Nations title in 2020 and this year they have finished fifth after defeat by Ireland in their final game. None of the players will deem that acceptable.
It is not necessarily up to the fans or anybody else to decide whether that is acceptable or not. It is the players who will be desperately disappointed because they know that they are better than fifth.
Look what they did to France when they beat them in the fourth round and look what France are doing generally. England are at that level.
They are up with Wales and France so it is unacceptable that they lost three games in the Six Nations.
You cannot see England play like they played against France and all of a sudden say they are a terrible team.
How do the players and management unlock that style of England player, with that intent and capability, so it becomes the default?
I know that head coach Eddie Jones will come up with excuses and say England cannot play like that every week.
But look at New Zealand, look at France - they have intent. That is how they want to play the game.
I think England have got to work it out themselves and it comes from the top. My concern is that it is not as joined up as we are all led to believe.
I am desperately trying to work out why you would not go out in Dublin and play with the type of intensity England had against France.
The conditions were perfect against Ireland. England were missing two players - Henry Slade and Max Malins - but it was pretty much the same team.
Why was there not the intensity to take quick line-outs and tap penalties? Why were they all of a sudden hugely ill disciplined? What has changed in a week?
I think it has to come from the management but the players still have a responsibility to step up. The senior players have got a responsibility to try to rectify it with the coaching team.
Matt Dawson was speaking to BBC Sport's Becky Grey.