I remember getting the crap scared out of me by the eel in Jolly Roger Bay when I was eight years old or so. Looking back on it, I think I was more terrified of what it might do than what it actually did. The first time I saw it, I had no idea what it might do if I got close to it, and I certainly wasn't going to try and find out. So I played past it, never getting that star for a rather long time. Being unwilling to find out just how scary it was made it even harder to stop being scared of it.
Now that I think about it, I did that for a lot of games when I was younger. The worm that hid in wells from Croc comes to mind. (Did anyone play that game but me? None of my friends know about it.) I think Banjo-Tooie was the game that finally got me to be less nervous. It was just so absurd that anything that might have been scary was just funny instead. I played that when I was 11 years old, and didn't play Banjo-Kazooie until a year after that. Now that I think about it, Kazooie was way less self-aware than Tooie, and a bit creepier, so if I'd played that one first, i likely wouldn't have had such a good impression of the series as a whole.
Interesting thoughts, I think.