The OP has a point. For most children's movies, that does seem to be the main plot device.

Things would go a lot easier for these main characters if they weren't such big liars.  Just tell the truth because you're always going to get found out.  Then, you end up losing your leg fighting a dragon or something.  Cartoons teach kids that lying is okay because in the end, you'll save the day and become a heroic liar.

the question should be Why are you watching all of these animated movies?? I haven't seen an animated movie since aladdin,which was foever ago.

I have a child and we go to the movies all of the time.  And whatever we don't see in theaters, we end up buying.  I'm a pretty big fan of animated films, anyway.  I'll probably still go see these films, even when she feels like she's too old to go to the movies with me.

I agree. It's also a big plot device in all romantic comedies. What's worse is when it is revealed, they never talk about it then and there. One side doesn't want to hear the explanation, even if there was a good reason. So they go off in different directions for about 15-20 mins worth of movie time and finally realize they still like one another. It is definitely time for some change.

This.  I have no strong feelings one way or the other.

But you are not the target audience for the film.  The target audience lasts only a few years of seeing these.  That being said, the plot device you describe is overused in all movies -- just look at any romantic comedy.

Mike from Morgantown

Erm, when did Megamind ever lie about being a good guy? 

Ok. I got a kick out of the OP.

That guy on the left.....that's Megamind.