Roy Keane says Manchester United will never taste Champions League glory again unless they stop making the same mistakes year after year.
The 1999 winners bowed out at the quarter-final stage for the third time in four years despite beating Real Madrid 4-3 at Old Trafford on Wednesday.
Having lost 3-1 in the first leg in Spain, Sir Alex Ferguson's side went out of the competition 6-5 on aggregate.
"We keep getting these lessons and the penny has to finally drop," said Keane. "We can't keep giving goals away to teams like Real Madrid.
"Once again we have had plenty of chances but we keep giving ourselves a mountain to climb and we haven't been able to rise to the challenge.
"We don't need reminding that we keep giving the same kind of goals away.
"We have had plenty of disappointments in Europe now. We keep getting to the quarter-finals but it is that next step of going on to win the trophies.
"A lot of teams get so far but it is going that final few yards."
But Ferguson insisted United can take comfort from playing their part in what he believes was the game of the season in Europe.
Ferguson insisted: "I was proud of the effort that the players put in.
"It was a pleasure to take part in a game of that nature. We had the best referee and the best game in Europe this season.
"Both teams produced football of incredible imagination that people will talk
about for a long time to come."