But the Chelsea defender will certainly have no problem recalling his first as a professional after he lines up against Bayern Munich in the Champions League final on Saturday night.
Cahill has already missed the FA Cup final with a hamstring injury, and said: "I was sick when I got the injury because I knew that was going to be the case straight away, although I tried to get back. But there was never any chance of that. That was a sickener for me because it would have been a big part in my career. So for me to make this one is a huge moment."
It is exactly the sort of moment for which Cahill left Bolton during the January transfer window, having never managed to reach a major final. Indeed, he admitted he did not know when he was last within touching distance of silverware.
"I couldn't tell you, probably in youth-team football," Cahill said.
"It's my first final and it's in the biggest competition - sink or swim. You come here to play in these competitions and be a part of this. We've got a great chance now to lift the best trophy in club football.
"I did win a few things as a kid, but nothing since. I can't remember what I did last week, never mind 10 years ago."
A Champions League final looked a million miles away when Cahill made his debut in the competition in February's 3-1 last-16 defeat at Napoli.
But the turnaround since could not have been more dramatic.
"It's been a mad season and a fantastic season for me," Cahill said. "Making a move here has obviously worked out really well. First to win the FA Cup and now to go into this huge game in my first six months here is really crazy."