Elaborate pretending as a child?
Interestingly what we have all described here is pretty much within the bounds of typical play activity for any child.
Most diagnosticians will look for a lack of imaginative play as indicative that a child may be on the autistic spectrum.
The idea is that a typical child will take a box of toys and make an imaginative story play with them while an autistic child is more likely just to line them up and sort them out.
For me, as a child I exhibited both types of play.
The role play I was involved in was usually instigated by others and I tried to go along.
When left to my own devices I was completely happy lining up my battery or matchbox collections.