He was the kid who scored the wonder winner to help the Hoops beat Barcelona in the Champions League.
And he was part of the side which failed to overcome Arbroath in the fourth round of the Scottish Cup.
While Watt described the night he made world headlines against Barca as the best of his life, his summation of the day Celtic drew with the Red Lichties was even more succinct – a freak.
Tonight, the 18-year-old hit-man would like nothing better than the chance to atone.
And, while visiting Gayfield will be a first for Watt – as indeed it will be for the rest of the squad – the kid, plucked from Airdrie United just two years ago, knows all about confronting and defeating difficult conditions.
Watt said: "The park is not going to be the best, and it will be different from what we are used to."
What they do know all about is the organisation and determination which Arbroath will bring to a tie which manager Neil Lennon describes as "another cup final for them."
They won many admirers for gaining a replay, but Watt has his own take on that draw at Parkhead.
"It was obviously a freak result for us, and we want to go and put it right," he insisted.
"They defended well and we had a few chances. We could have scored a couple and, to be fair, they had chances.
"This time we need to be clinical and do what we can to get into the next round."
Lennon made several changes to his line-up for the first meeting, but that was because they were about to play a crunch Champions League tie a few days later.
This time, progressing to the fifth round of the Scottish Cup is the priority – along with avoiding what would be an embarrassing exit.
The manager has promised to field a very strong side, and Watt said: "Hopefully, I will be involved. If I am on the bench, then I need to come off it and score a goal or two."
Having gained his grounding in the game in the lower leagues, Watt is well placed to understand how motivated Paul Sheerin's men will be for this game, which will be screened live across the UK and beyond.
"For Arbroath, it will be the game of their lives," he said. "They are not going to play Celtic every week."
Now Watt just wants it out of the way. Celtic do not want, or need, any more postponements or delays as their season is already heavily congested.
But Watt is delighted the December schedule is so packed, because he believes it gives him more chances to get the game time he needs to help his fitness levels.