I only met my paternal grandfather once, just before he went to Australia where he promptly died! I knew my maternal grandfather but he was distant and visits were very formal, stuffy occasions. My step-grandfather was a man to steer well clear of if you were a little girl, if you get my meaning!
However, my sons were lucky with their grandfather (my dad) and my granddaughter has a brilliant step-grandad in my OH. They are devoted to each other and she (aged 3) gets him doing all manner of hilarious things. It's lovely to watch...I think we all deserve(d) a lovely grandpa!
I've got another 'keen'... Ouch!