Tears of Worry??

This past Saturday night while Jason was at Addicted working, me and the boys stayed home and watched movies.  Of course me and Dayton couldn't agree on the same movie. So he watch "Fox and the Hound" in my room. And I watched "Thorn Birds" in the living room. 
I folded laundry while I watched my show.  When it came time to put some of the clothes away I walked into my room, and looked at Dayton on my bed.  He had tears running down his face and was really upset.  I looked at the TV screen to find it at the part where the Grandma has taken Todd (the fox) out to the middle of nowhere, and dropped him off, and was driving away without Todd. 
When I was a little kid, this part of the movie also upset me... but I was around 6 or 7.  Dayton is 3 almost 4, and it affected him to the point of tears.  He looked up at me and said "Mom she is leaving the fox and he is sad and scared". I really didn't know what to say.  I mean what do you say?  Yes, the fox was scared and alone.  How do you comfort a 3 year old over this?  I told him "the fox is brave and he makes new friends just keep watching, it will be okay". 
Dayton kept watching his show till it was over.  He reported that he liked that movie.  He was no longer upset, sad or crying.  He told me that he was tired and he went to his room, and went to bed without a a problem.

Two days later and I am still shocked that Dayton understood enough of what was going on, to cry over it.  He understands fear, and loneliness to the point it affected him enough to cry!  I don't understand how HE understands.  He is never left behind and all alone to know how Todd would feel.   I cant even wrap my head around it.  I guess it turns out that he is a soft hearted little boy who sees and understands a lot more than I give him credit for.