One of the surprises about becoming a grandparent is being able to observe and pay attention to the developmental process of a new human being. I missed this observation when I was a parent, most likely because I was spread too thin and focused on completing too many tasks. BUT, as a grandparent, you get a front row seat to watch this evolutionary process unfold.
For example, in this video, my 3.5 year old grandson, is talking about monsters. This is the FIRST time I have heard him conceptualize something he hasn't physically witnessed or seen, and he is making up the descriptions of these monsters as he goes along, giving them feathers and colors and personalities. THIS, absolutely amazed me. THIS video made me aware he had an imagination spark that went off and his brain is now seeing and experiencing more complexity than he did just a week before. I was in total awe!