It is a strange thing. It comes around and you have to be careful.
Before the second leg of Lyon's Europa League quarter-final, West Ham manager David Moyes warned them.
The Hammers had secured their first European semi-final in 46 years, and they were celebrating a three nil victory that helped rid the club of some of the pain that had built up after the first leg.
The West Ham manager or his players were not surprised by the wink that Dembele gave after drawing the foul that saw Cresswell sent off.
The official account of Lyon did not send a message. They were asked if there was a chance they wouldn't make the final four.
At full-time, Declan Rice joked that those things come back to bite him.
There were a few incentives tonight. In the first leg, Dembele winking at the camera and then their admin said they couldn't see how they would get through.
We stayed quiet, put in a performance, and now West Ham are in the semifinals.
Eintracht Frankfurt, who upset Barcelona in the last 16 of the European Cup Winners' Cup, will face the side that defeated them in the last four of the 1976 European Cup.
Rice said that it feels very, very special. You shouldn't be playing football if you can't get up for the games. The fans roared for the warm up. It makes you want to go and perform.
He said that for them to beat Barcelona, they are a top side. We will be ready for anything. We know what we want and we can reach the final.
Antonio told the Footballer that he believed West Ham would win the Europa League.
That dream is one step closer after Thursday night&s excellent display.
The Hammers advanced to the next stage after topping their group and eliminating Sevilla.
The only teams left in the competition are Frankfurt and Rangers, both of which were involved in shock wins at the Nou Camp.
Leon Osman said that they have a different issue coming up. Until this point, it was a case of let's see what they can do, enjoy the trip.
With Barcelona leaving, this competition has opened up for them. They could win a serious trophy now.
You could call them favorites at this point. There is a different kind of pressure. It is something else they have to learn to deal with.
The Hammers have two weeks to prepare for the first leg of their semi-final against Frankfurt, in London, with the away leg taking place one week later.
The whole of Europe will be watching this performance.
Players will want to join this team if you win this competition. The team is trying to bring European success. It is a huge statement.
The progress made in less than two and a half years since West Ham appointed David Moyes for a second spell has been clear.
The Hammers were 17th in the premier league when David Moyes took over, but are now fighting for European silverware.
Joe Cole, a former West Ham player, said that it was incredible. It was a disciplined performance. Everything you need to be a winning team has been instilled into this team.
They have a balance between being passionate and cool. No one can do any wrong. He is at his peak as a manager, he gets it right all the time.
Football is like a movie. It is scripted. It is Frankfurt again. Mark Noble is last year. The draw is not as bad for West Ham. It would have been great to go to Barcelona, but now people at the club believe they can win this.
Carlton Cole is a pundit. I cannot explain how different this feels.
Being a West Ham fan, you don't go through these emotions. You couldn't write this at the beginning of the season. It is very realistic.
Simon Stone is a reporter for the British Broadcasting Corporation.
One of the Hammers all-time great performances has been delivered by David Moyes. Their biggest win in Europe was the three nil success.
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Hammers fans have waited a long time for that promise to be fulfilled and there has been a lot of resentment felt along the way.
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