Almost 60 by the time he replaced his dour predecessor Georges Leekens, Waseige was thought to be past his sell-by date.
He underwent heart surgery last April and now walks five miles a day.
His first game in charge was a 5-5 draw with Holland, with two goals from Derby County's Branco Strupar marking his first international start.
With the exception of Euro 2000, where the pressure clearly told, results have generally been good.
Waseige has added youthful talent to an experienced core of players who were regulars under Leekens, such as Schalke 04's Marc Wilmots, Gert Verheyen, of Club Bruges, and Bart Goor of Hertha Berlin.
According to Verheyen, Waseige has given the team some much-needed self-belief.
"We used to play 4-4-2 with a lot of players behind the ball and never adapted to the opposition," Verheyen told BBC Sport Online.
"Now we have confidence in our own ability and it shows."
Goalkeeper Gert De Vlieger, of Dutch first division side Willem II, is also full of praise for the coach.