It's a wonderful movie. Pixar did really well this time! SPOILERS: I especially liked how the moral of the story was that it is ok, and sometimes necessary, to express sadness. The rest of our culture is obsessed with telling us that we ought to be happy all the time, and if not, we should consume until we are. Inside Out was a welcome and refreshing corrective to this.
More spoilers. I thought the moral of the story was more about growing up and how when your environment changes the way you interpret memories also changes. For example when I was a kid fishing with my grand father always made me happy now that he has passed those memories are bitter sweet. That's why Sadness was trying to touch Rileys core memories with blue before everything else went down. Those were no longer happy memories.