I initially dreaded the grandparent journey -- even to the point of insisting that I would only be called "Mr. M...." and forbidding any reference beginning with gran.... anything (much less the "pee-pee" they were proposing).
Of course, that did not last (too long anyway). I finally decided to just consider myself fortunate not to have been a grandparent before I was 40. Like I said before, all a matter of perspective.
Now, I find it is great revenge, er, I mean fun. The only part they do not like is that I swore off diapers 11 years ago so he sometimes sloshes a bit longer than they would like.
When my oldest two were very young, my wife's father used to call and invite them to ask me where I was keeping the candy he had given me to give to them. Of course, I had not seen him in weeks and had no candy. I am looking forward to that moment in a few years.
Troy