I believe Emmet's movements can be explained in a similar way as in Toy Story.  The toys each have an individual personality and autonomy, but those personalities and autonomous actions are affected by the person playing with the toys.

This would mean that a large portion of the movie consisted of the characters acting in and of themselves.  This makes sense if we consider the people making fun of Emmet, as I don't think that was Finn nor his Father.  Furthermore, if we consider the lore of the world (The vortex, the Kragle), these things would make sense if the characters would autonomous, (If a lego person falls off the table, he'll just pick him up).

While it is definitely possible that a child would imagine this on his own, I think it makes more sense that the legos are autonomous all the time, but given personality from the one playing with them.

What are the implications of Emmet's autonomous movement?
When it comes to mortgage advice, some people recommend making an extra payment. The logic is :"These extra payments are automatically applied to your principal, not interest".

Why does it matter if the extra payment is applied to the principal and not interest?
