What Happened? Name Changes and Life Stages

Isabella, first granddaughter. 

My teenage daughter broke up with her boyfriend this week, and my son, (who is currently serving a 14 day sentence cutoff from communication with the outside world), has been nominated for best personality at school.

Seems like one day you just wake up, discover a new ache, look around and the whole world has shifted. Perhaps not suddenly, but the gradual changes and small things that you don't quite put together, or associate with any meaning. Until something catches your minds eye and you pause....and say What Happened? 

I didn't notice it at the time, but my name was changed to Joseph's Dad about 3 years ago when he started playing football. Of course the focus is on him.  At work I have a personal brand and everyone knows both my first and last name. Jennifer is a teacher and at her school I'm known as Mrs B's husband. It's been like that for quite some time. To my teenage daughter I am known as Joe, Dad (and Step-dad, to those she feels closest to). I'm used to these names, they work for me.   

I need to pick out a grandpa name. Don't freak out, no breaking news, it's for the grand-daughter I already have, (she's two< lives out of state, and of course is too precious) but also for those perhaps to come. I want to make sure I don' t get stuck with some name that doesn't work for me. I'm looking ahead to the time when I'm the old man in the room, where the dominant adults in the room are the present day and future grand-kids, what will they call me? Most of the time, the grand-child just starts calling you something and you have no choice what that is, that becomes your name from that point and into the future. And, they can change it or shorten it anytime they want.   

Grandpa, Pops, Tito, Pawpaw, Pee-paw, Saw-zaw, just doesn't work for me. My daughters call one of their grandmothers, Tutu, Hawaiian for grandmother and that's fine. The other grandmother is known as Grandma Marching. Again that's fine but I think I want to choose mine. I will figure out how claim it later.

I heard a story of a woman who is selling the naming rights to her baby for $5000. I'm not going that far with it but I think I would be open to hearing other ideas. I'm not crazy about the names above and I'm working through my own list. So far, I'm looking at "G-pa" but I probably won't be a hip-hop friendly grandpa, I got to get this name thing figured out before my name gets changed again or assigned to me for life. Life marches on.