Liverpool manager Jurgen Klopp wanted to punch himself after failing to sign Sadio Mane at Borussia Dortmund, making it "very easy" for him to decide to bring the forward to Anfield.
The German considered taking Mane - then at Red Bull Salzburg - to the Bundesliga in 2014.
But Klopp ensured he completed the signing two years later as Liverpool paid Southampton £34million for the Senegal international.
Mane has helped his team to the top of the Premier League with six goals and two assists and Klopp said it was a straightforward decision to make a second time around.
"With Sadio it was pretty simple because I made the mistake at Dortmund where I didn't take him," Klopp said.
"We talked. I think everyone knows we met each other and by the end I didn't feel this [claps hands together].
"Around about three months later I would have punched myself so I knew already that the next chance I had I would take it. So it was not difficult to take this decision, it was very easy.
"When the club came and when Michael Edwards [Liverpool's new sporting director] said we have an opportunity. No talks were necessary any more. It was a case of 'let's do it'."
Mane returns to St Mary's on Saturday as Liverpool visit Southampton looking to extend their 12-match unbeaten run in all competitions.
Klopp was unsure why he opted against signing the 24-year-old the first time, but is happy to have him now.
"I don't know why I didn't sign him before. I like the player, it was more of a feeling," he said.
"At Dortmund we could only get one player for this position, not two or three, so it needed to be exactly the right fit in this moment.
"I've said a lot of times, I'm not a genius and I couldn't exactly imagine where he was in terms of playing in the Austrian league and what does the Austrian league mean for the football [at Dortmund]?
"I have made more mistakes in my life like this but he would have been more expensive if we had taken him to Dortmund and then he had been sold to Liverpool, so all good for Liverpool. The more I think about it, that was my first Liverpool decision. Nice."