The Celtic goalkeeper can certainly enjoy a sense of personal vindication when he faces the club who handed him a free transfer back in the summer of 2011.
But Bain insists he harbours no hard feelings towards Aberdeen and now reflects on their disposal of his services when he was 19 as the making of his now upwardly mobile career.
“It was Craig Brown and Archie Know who were in charge of the first team there at the time,” he recalls. “I didn’t see it coming, to be honest – I thought I’d get another deal at Aberdeen no problem. But it was probably the best thing that ever happened to me.
“I was in the youth team for two years, then signed as a first team squad pro in 2010. I was on the bench for the first team maybe three or four times, but never played.
“I went on loan to Elgin City during that season, and I really enjoyed it. Playing games and making mistakes in a league that no-one was really watching was a good thing for me.
“I learned a lot in my time at Aberdeen, working under the goalie coaches Jim Leighton and Colin Meldrum – who is now at Celtic with the youth team – and I’m thankful for the time I spent at the club.
“It was lucky for me that Paul Hartley was leaving Aberdeen and getting the manager’s job at Alloa at the exact time I was released. He obviously took me straight away and that got me playing games and enjoying it again. Everything happens for a reason and you make the best of the situation that you are put in. I worked hard at Alloa, it was long days and long nights, but it is all worth it now.”
Bain is gratified by the opportunity to play in his first major final this weekend with Celtic manager Brendan Rodgers sticking by his pledge to play Craig Gordon’s deputy in domestic cup fixtures.
Such arrangements at other clubs often see the recognised first choice keeper restored for the showpiece fixtures but Bain was always confident his opportunity would come this season.
“We had a brief conversation about it in the summer and the manager has always been a man of his word,” said Bain.
“Because of that, I thought I would play in the final. I feel I’ve done well in the games I have played for the first team this season and I think he has been happy with me.
“It’s good that he’s shown faith in me to play in the cup games until now so to go another step and play in the final is great. It’s a real boost for me that he’s got that belief in me.
“I don’t know if it will apply to the Scottish Cup as well. Hopefully if we go on and have a good performance on Sunday, that could be the case.”
Bain will be making only his 12th appearance for Celtic since making his debut in the 3-2 league victory over Rangers at Ibrox in March. He is relishing the chance to showcase his ability and deliver a riposte to those who were critical of his call-up to the Scotland squad earlier this month ahead of goalkeepers such as St Johnstone’s Zander Clark, who are playing regular first team football at club level.
“I saw a lot of things said when I was included in the Scotland squad with people mentioning how I wasn’t playing a lot of games,” added a clearly irked Bain.
“But I play and train at Celtic every day with the best players in the league. So I don’t know what better preparation you can have. I have played over 250 games now at 27 – and I’ve played for Scotland before. So I’ve got a lot of experience in that sense. I feel I’ve got the best preparation here with the best facilities with the best players every day.
“I felt my inclusion was justified. Listen, it didn’t really annoy me but I just feel when I’ve come in and played I’ve been competent and done well. The fact I’ve played a game every three or four weeks hasn’t really affected me. I definitely feel I’ve become a better goalkeeper at Celtic.
“Everyone is here to make me improve and I feel I have done. Being put in the situation of not playing and then playing has also helped me mentally.
“I’m 27 now so if I can get another good few years at this club I’ll just keep steadily improving. I don’t think I realised the magnitude of Celtic until I came here.
“I’ve really just tried to enjoy myself. That’s probably stood me in the best stead possible. I’ve just enjoyed playing in the games when I’ve been picked.
“I’ve enjoyed being around the lads and enjoyed learning and improving. Mentality wise, it’s been quite easy because I’ve just been having a good time. But I can see how some players could be overawed by a club of this size.
“My mentality has always being quite strong. It is a game of football, a game I have played since I was 10 years old so I have just tried to embrace it. Sunday will be good. The only time I’ve played at Hampden before was for Alloa against Queen’s Park, so this will be a bit different.”