As a straight man, the former Packed To The Rafters star, who plays gay man Timothy Conigrave in the adaptation of his memoirs published in 1995, said it was an eye-opening experience when he held his co-star Craig Stott's hand in public.
"We held hands walking down Chapel Street (in Melbourne) and I had my first, first-hand experience of a number of things," he said.
"We walked into a cafe and ordered a coffee and by the time they turned around we were holding hands and just watching the way the person serving us changed their opinion, it was my first experience of discrimination.
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READ NOW"I haven't grown up like that. Craig identifies as queer and probably understood this more innately than I did."
Though the film tells an emotional story about love, infidelity, discrimination, the fight for acceptance, disease and death, Corr said the atmosphere on set was generally light-hearted.
"There's a scene not in the film and it transcended acting for us; the take went for 45 minutes and we spent so long with these boys that it really felt like we were saying goodbye to them ," he said.
"But there's a lot of humour and hope and Tim's book is very funny. By all accounts, (Tim) had a clowning quality to him; he was an entertainer.
"It was vitally important that we found that balance.
"Apart from the last two weeks, which were emotionally difficult, and the weight of what we were doing was driven home, it was a lot of fun on set.
"Being boys in the schoolyard and representing young love and all those awkward prepubescent moments in the '70s and '80s with all those Flock of Seagulls wigs on, looking like our fathers and mothers, it was a lot of fun."
Holding The Man is in cinemas now.