Chris Coleman knows he will never get Serbia out of his system no matter what happens in Belgrade on Sunday night and said he and his team are ready for "shenanigans" surrounding the match.
Coleman is a national hero these days and recently picked up an OBE at Buckingham Palace after guiding Wales to the semi-finals of Euro 2016.
But Coleman admits that a 6-1 defeat away to Serbia in September 2012 was the lowest point of his five-year reign and will never leave him.
That nightmare in Novi Sad nearly left Coleman teetering on the brink almost before his tenure had began.
And the Wales manager admits the painful memories came flooding back during a World Cup reconnaissance mission earlier this year.
"As soon as I got off the plane I felt it,'' Coleman said ahead of Wales' Group D qualifier in Belgrade. "It was only a reccie but I had butterflies in my stomach. I thought 'Here we go again, I remember this place.'
"I can't say this is another game in the group because it's not for more than one reason. And one of the reasons is that.
"I suffered there, we suffered there -- and it was my fault. That will never leave me.
"I think it would be like that if I went back to Belgrade with my wife for the weekend!''
Wales face another daunting test in the Balkans in attempting to keep their World Cup dream alive.
Star man Gareth Bale is missing through suspension and James Collins, Neil Taylor, Andy King and Hal Robson-Kanu are also absent.
Wales are unbeaten in World Cup qualifying but trail Serbia and the Republic of Ireland, the top two in Group D, by four points at the halfway stage after four straight draws.
More than 40,000 are expected to greet Wales at the Rajko Mitic Stadium and the hostility levels are expected to be turned up to maximum.
"You go to these places and it's almost like a stage in the game where there's a power play,'' Coleman said. "All of a sudden, from wherever it comes, the crowd start getting really rowdy.
"The opposition up the tempo for five or 10 minutes and they bombard you. You stand up to it or you duck it. There's no third option.
"This will come in Belgrade and you need to answer those questions, physically, mentally and tactically.''
But Coleman feels his players are prepared these days for what he calls "shenanigans."
"Countless times I've been away on international duty as a player and a manager, little things which people probably wouldn't see,'' Coleman said. "But the more you're in it, you see it's not by coincidence.
"The journey from the hotel normally takes 20 minutes and they'll say 'You know what, tonight, we've got to leave now because it will be mayhem.'
"So you end up getting to the stadium 30 minutes before you want to be there. All things like that are meant.''
