Me too. When I think of their birthdays, weddings, all those things along the line that Michael will not be with them for I just feel so so sad. When I think of them growing up without Michael's influence it upsets me too. Blanket is so young. But I think Prince and Paris are old enough to continue to teach him in a way - they know what their dad expected of his children; all the things Michael considered important in raising them.
Also regarding the children, I just get sad so sad at what's happened to them. It's unbelievably awful.
Other things that set me off:
the thought of how much pain Michael was put through by the world,
the thought of Michael being sad and lonely when he was alive,
the thought that Michael had a hard life and didn't get a chance to relive the good times,
the thought that Michael wanted to have his children experience a Michael Jackson concert, and they never got that chance,
the thought that Michael wanted to bring the children on stage and "introduce them to the world" (as said in the 2005 Geraldo Rivera interview) and he never got the chance - that happened at his memorial,
the thought that Michael died maybe thinking that a lot of people disliked him,
the thought of the pain Michael felt at the ridicule he endured,
the thought that he's no longer on this earth.