For most of us, keeping the faith with your football team is a non-negotiable.
Us mere mortals have no reason to go changing teams, no matter how much they frustrate you, as our fandom will be one of the very few constants during our lives.
But for aspiring footballers, there may be times when your loyalty is put to the test, as you have to go against the team you love for the betterment of your career.
Kenny Dalglish on crossing the Old Firm divide
As rivalries go, the Old Firm is up there with the very best of them. Swapping sides in Glasgow is not for the faint of heart, but it’s something that Rangers-supporting youngster Kenny Dalglish had to do.
When he was 14, the young Dalglish moved into a newly built tower block in Ibrox, overlooking the Gers’ home.
“My dad took me to Rangers from an early age – that never caused me any bother later on, you have to support someone when you’re a kid,” Dalglish tells FourFourTwo.
The football-mad youth went to work as an apprentice joiner after leaving school, by which time he was being touted as a rising talent in Scottish football. Turning out at weekends for Glasgow United, scouts from West Ham and Liverpool visited. His next stop lay in his home city – but not at the stadium he could see from his bedroom window.
“One day we played Celtic’s young boys,” Dalglish remembers. “Among those watching was their first-team manager, Jock Stein. He liked the wee No.4 – thankfully, that was me.”
Stein’s assistant, Sean Fallon, paid a visit to the Dalglish family home and, surrounded by Rangers memorabilia all over the walls, asked Bill and wife Cathy if their son would be interested in joining the Catholic juggernauts.
“I told my dad, ‘I thought you’d have wanted me to play for Rangers,” Kenny would later recall. “He said, ‘Son, the best place for you right now is at Celtic.’”
Dalglish senior would quickly be proved right, as only a few weeks later, Stein’s side were crowned European champions in Lisbon.
“I can remember watching that game,” says Dalglish. “Jock became the first British manager to win the European Cup, and he did it all with a group of players that came from a 25-mile radius around the city.
“Those scenes and the celebrations in Glasgow sparked a lifelong ambition to get my hands on a European Cup. This was the club I was joining.”
Asif Kapadia’s documentary film Kenny Dalglish is now on Amazon Prime
