My eldest is 4 and doesn't seem to pretend anything, she's very logical and a realist. She's been like this as long as I can remember.
Once I thought I'd try her out, she was sat on a teddy so I picked it up and said "Aww you're sat on teddy and she's crying!" so she took it off me, threw it across the room and said "It's not real Mummy!" On the flip side of that when I had Swine Flu, everyone was either working away or on holiday and I had a week of it alone, she was only 3 but she took charge, wrapping me in blankets from her bed and her dressing gown and bringing me "hot chocolate" (in upside down mega bloks sadly 
) and supporting my head whilst I "drank" and she looked after her sister.
Yesterday we were invited to children's university to do a study and the lady who played with her whilst I was in with the youngest commented that all her play had been about sorting things out. She played with the food by lining it up on the floor in sets and the dolls house she organised. She played with some playmobil skateboarders by putting them on the roof of the dolls house and rolling them down, which isn't pretending anything just something fun. She got a kitchen for Christmas and makes us food and drink then when we go to eat or drink it points out "it's only pretend!"
She's quite bright and picks things up really easily and likes to push out whatever she asks about - like wanting to know why there was water on the curtain rail ended up being a lesson in clouds and rain! She'll suss out Father Christmas before she's too old, she's already asking questions! She was premature and ended up going up a school year so I don't think she'd have coped with another year of nursery, where she "should" still be. We said when she was in NNU she'd be a whyer. She never slept, she had to see what every noise was - being under lights was a nightmare because she hated not being able to look around and kept trying to take her goggles off.
I'm not worried about her, I've just never known another child be so realist and wondering if there are any other parents of realists on here.