I totally get what you're saying Gooseberry. I mean, I don't run around telling anyone who might listen that I'm a 'cultural Christian' as that would indeed be wanky. I don't describe myself using those words, ever, but they could be used to describe how I live my life.
So, I was raised Catholic but am definitely not a Catholic now. Nor are my parents or siblings. However, we celebrate Christmas and Easter. My parents still put out a crib at Christmas. I love Christmas carols.
My Granda only ever stepped foot in a church during the last 40 years of his life for funerals and memorial masses for his son (which are arranged for my Nana, who is religious), yet when he died, within an hour the whole family were gathered in his hospital room while a nun led a decade of the rosary.
Essentially, while none of us practice Catholicism, we still engage in the cultural practices. So no praying or attending mass, I'm not having a church wedding. But we like listening to carols at Christmas, my Mum always makes pancakes on Shrove Tuesday, and we bless ourselves when an ambulance passes. Though that last one may be more an Irish thing than a Catholic thing 