Just gets harder, not easier

So today was grocery day.  So mundane.  All of a sudden I passed the baby food aisle in Food Lion and almost had a panic attack.  It occured to me that Caroline would be 4 months old now and just starting on baby food.  I'm always doing stuff like that.... what would she be doing now?  Rolling over? smiling?  What milestones would she be reaching?  
 
Oh the pain of this can be just too much to bear.  For some reason it is getting harder, not easier.