Funny, I always pictured the brain a bit bigger. Maybe due to TV series and such and because I couldn’t really judge what the size would be based on the head.
It sparked a controversial question in my mind, does a bigger brain make you smarter (so big headed people could be smarter). One page I came across (which looked at least a little legit) was this: Stanford Ask a neuroscientist
I used to think the same, until I read somewhere that our brain is pretty much the size of our two fists if we put them palm-to-palm. Looking at my own hands that way is a great reminder.