Is it normal to think vocally internally?

Often movies have come up where someone can read thoughts.
The process works like people talking to themselves in their mind which the person can now hear.
Examples are like in heroes or what women want. (all i can think of off hand)
I've done a quick survey and everyone i've talked to seems to say the same thing.
They all talk in their minds... things like " i wonder did i turn the light off" or "he's such an idiot"
and heres the kicker... i dont.
I do a lot of thinking but hardly ever in words... the odd time if i needed to keep something in my head like a phone number or a name i'd say it over and over or recite memorised material if i was trying to revise but thats hardly ever.
What do you guys reckon of this?
Without sounding self absorbed, i'm quite intelligent as well but often the depiction is (especially in "what women want") that if you have no internal thoughts then nothings going on and you're quite dumb... Can someone shed some light?