That glorious, sun-drenched afternoon in Bordeaux, when Wales marked their first appearance at a major tournament for 58 years with a dramatic 2-1 victory over Slovakia, evokes so many happy thoughts for Coleman, although the moment that will live with him for ever has nothing to do with anything that took place on the pitch.
Lose in Belgrade and Wales can all but forget about qualifying for next year's World Cup in Russian Federation.
Vokes will reach his half-century of caps nine years after making his debut in a 1-0 friendly win over Iceland in May 2008.
"We've tried desperately hard to move on from Euro 2016, but you still keep it in the back of your mind", said Coleman.
"When the national anthem started, that's what I'll always remember, the noise". God, it was unbelievable. It was absolutely incredible and that's why it's so hard to get to these tournaments. You have to deal with it at worldwide level, and we've experienced it before home and away.
And, without the suspended Gareth Bale, Coleman knows that his players will be up against it at the Stadion Rajko Mitic. To compound matters, Hal Robson-Kanu withdrew from the squad on Thursday and added his name to an injury list that includes James Collins, Andy King and Ben Woodburn, leaving Wales looking rather depleted, especially in attack. "You need to answer those questions, physically, mentally and tactically". Whether it's Serbia away, it doesn't matter.
"A little bit of focus in the right times in games, mental sharpness, that's what we've got to get back".
"Gareth's [absence] can't affect us. There's everything to play for and it's a great game for us to be involved in". "I'm optimistic of getting a result in Serbia".More news: Police say car hit pedestrians in Amsterdam
The Burnley man scored five goals in as many games at the end of last season and is ready to lead the line in the crucial qualifier.
Defeat in Serbia would therefore raise doubts over his future, a scenario which seems barely believable given the unprecedented success of recent years.
"This campaign when we've drawn it's been like a defeat because of what's happened between the Bosnia game and drawing in Austria".
"Tournaments are fantastic places to be, but you have to go above and beyond to earn it".
I think we've seen that before in the past. "But we're not far off where we need to be".
"Wales are a risky team who have played together for a long period".
But most of all Coleman is an optimist, insistent Wales can secure a vital result in Serbia and give a nation reason to believe again. I think we've seen that before in the past.
"It is like a "six-pointer" because if we win we will have a big gap (on Wales). That's what we've got to get back".