It is almost as if the gods conspire to push their resolve to the limit.
For example, if, in real life, they are in a long-term relationship that crashes, sure as fate they will soon find themselves cast in a play in which their character has to endure a break-up.
This week, Kate Donnelly's character resolve is certainly being stretched.
She is starring at Oran Mor, Glasgow, in Grave Undertaking, a play by Paddy Cunneen in which she plays a corpse in a funeral parlour.
However, the corpse, Margaret Gray, comes to 'life', in the imagination of funeral director Jim McCaber (Jimmy Chisholm) as he realises the body he is about to embalm was once his girlfriend for 12 years.
"He has all these memories and it's about the arc of their relationship," says Kate.
The offer for Kate to appear in Grave Undertaking arrived shortly after the death of her father, Paddy.
Just as she was coming to terms with the loss of the former shipyard worker, 89, the play saw her re-confront the mortality issue, and revisit the very understanding of loss.
"The play is about grief and letting go," she says. "It's about life and love and loss. And yes, when I was offered the play I felt fate played a hand in it all.
"I had been planning to have a rest after my dad died, and I was thinking of going to Arran, where the family had arranged to go with my dad before he took ill, and say goodbye to him there.
"But then the play offer came up and I found I was back in this world of death and embalming and everything that goes with it."
The actress, who is married with a daughter, 19, adds: "What was hard for me was the emotion of the play. At the end of rehearsals I felt I needed a good howl."
Yet, that is not to say Kate considers the content of the play to be depressing.
"It's also about love," she says. "It is about what it is like to be attracted to someone. It is also about how people get comfortable in relationships, but it is a reminder we should not get too complacent.
"We should remember change is inevitable, and make the most of our loved ones while we can. Let's enjoy the moment.
"My dad was exactly that type of person. My mum was the worrier. My dad was the one who would always look for the positive and since he died I have found myself trying to be more like him, trying to embrace his philosophy."
Kate grew up in a family of six children in Pollok and realised she wanted to act after appearing in school productions. She studied English and Drama at university, then went to do a post graduate acting course in Wales.
"On returning, I worked in a sketch review, Red Heads, with Peter Mullan, Libby McArthur and Peter Arnott and got my Equity Card."
Kate has worked regularly in TV over the years, with roles in well-known Scottish dramas, such as River City. She also regularly played Frances the librarian in Still Game.
Yet, she is also a writer. Kate teamed up with partner Clare Hemphill to create the powerful STV drama, Cracked, set in a rehab clinic and which Kate also starred in.
"I love writing," she says. "You get more power when you are writing. But I love it all."
Kate is also a qualified Cognitive Behaviour Therapist. She has long been a student of human behaviour, and now the qualification gives her the chance to explore the subject further, and help others.
"I am fascinated by what makes us tick, how we prioritise things, what is important to us," she says.
But she won't work full-time as a CBT counsellor. "It's fantastic to do, but I think part-time is enough. It's about balance in life."
Meantime, she has the chance to be the corpse in the new play.
"And I'm thankful," she says. "It's been difficult at times rehearsing, given the subject material, but Paddy Cuneen's writing it terrific."
She adds, grinning: "The world of the funeral parlour is a great one to explore. And there is music in the play (performed by one of Jim's most successfully embalmed corpses). "How can you go wrong?"
l Grave Undertaking, £8-12.50, 08444 771000. Starts 1pm.