My daughter is 13 months old and like your little one she is the most laid back child I have ever seen. Just like you said, entertained herself, stayed in the stroller etc.... She still does for the most part but here recently she has started throwing little tantrums when she does not get her way and she now wants to get out of the stroller. I think she is now able to understand that she can be more independent. She is developing a personality of her own. Instead of just dealing with what we give her to play with or ride in, she wants what she wants. More times than not my daughter just wants to crawl,try to walk or get to the unknown object on the other side of the room. She is still a great child but every day I see more of her own personality coming out. When I sit back and watch, it is amazing to see what she can do. I then realized she is getting older and is no longer the little baby that would lay on the floor and stare up at the moblie or be content with the few toys laying infront of her. Your little one is probably ready to see the world. Hope this helps, and enjoy....this is the best part!