The devotee took to social media site and recalled bonding with his dad as a kid, when they watched Terminator 2: Judgement Day together back in 1991, and he decided to check out the new instalment together, as has become their tradition, on his birthday on Wednesday (01Jul15).

The fan admitted his dad had lost interest in the movies he had been so passionate about since suffering a health setback in January (15), as he continued to battle mild dementia and schizophrenia, but seeing Terminator Genisys on the big screen appeared to give him a little lease on life again.

He wrote, "I was actually surprised to see my dad enjoying it, not because it was this amazing film we never seen before but because for MONTHS he hasn't smile (sic), he used to be a very happy man and always had a big smile on his face. I know it may sound dumb but it felt like a miracle!

"Thank you GovSchwarzenegger (sic), for making my father smile again."

The heartwarming post prompted a slew of sweet responses from other Reddit users, but it was a reply from Schwarzenegger himself which left the man stunned.

The actor wrote, "Wow. I'm in Korea on a whirlwind tour but you stopped me in my tracks. This is so touching. Thank you for sharing. I'd like to say 'this is why I do this' but you should know it was you who made your father smile. It was your presence and caring. Happy birthday, you've got a lot of wisdom for 30 years."

Schwarzenegger also attached a handwritten note addressed to the fan's father, praising him for raising such a wonderful son, and the fan confesses he was blown away by the reaction.

Returning to the site, the user writes, "I am completely overwhelmed! So many emotions going through right now! Thank you so much GovSchwarzenegger I really don't know what to say?! Made me cried so much (of pure joy), we needed this. seriously, thank you from the bottom of my heart."