Following her first graduation Pat decided knowledge was "fantastic".
"But the more I've learnt, the more I realise I don't know", she said.
Another degree followed in 1994, this time a BA in history from Teesside University.
She said: "I was just curious.
"I wanted to know the difference between an OU degree and one from a traditional university."
'Very proud'
While working as a sub-postmistress in the ex-mining community of Charltons, near Guisborough, she became interested in its local history.
"I would hear little stories by the ex-miners and their wives", she said.
"It really enthralled me. I collected memorabilia and taped interviews.
"And then my son got a masters, my great niece got a masters and I thought 'I think I will try and get a masters as well'."
This time, she once again opted for the OU.
She had not attended her two previous graduation ceremonies, but her family insisted she did this time and were there to see it.
"My son was overwhelmed", she said.
"When I walked on the platform there was tears running down his face."
Ivan described himself as a "very proud husband, with a very clever wife".
He added: "I am showing her photo in her gown to anybody who stands still long enough.
As for the future, Pat is "thinking" about a PhD.
"I am 80 in September so maybe I should call it a day, but I don't want to.
"You are never too old. If you have got any doubts, just go for it!"
