Anyone seeing the TARDIS arrive somewhere probably thinks they’re hallucinating or dreaming. It doesn’t drift gently down from space to land on a planet, instead it simply appears, often inside existing structures.
It materialises gradually before the astonished eyes of witnesses, fading in and out accompanied by a grinding, droning sound until at last it achieves solidity, looking like little more than a tall, blue wooden box with a light on the top.
Even that’s deceptive; the interior of the TARDIS far exceeds its exterior dimensions. Small wonder people looking inside can’t believe their eyes.
The Doctor cherishes their reactions.