Kids are baffling creatures for sure! My son was very daring as a toddler and would do anything that he was tall enough for (basically the rides without height restrictions, like Haunted Mansion, Snow White, etc). We then went to Universal when he was 3yo and he was scared by many things. Didn't like Spiderman because he thought he was falling, any simulator, ET (even though he'd been on it when he was a toddler), etc. He did think that Jaws was funny, though.
Then we went back a year later and he liked everything. I also brought him to WDW in that same time frame and he liked everything that he was tall enough for, except for not wanting to do Dinosaur antoher time (did Tower of Terror 5 times with me).
We'll see what he enjoys and is scared by this next visit, when he's almost 5yo. He'll be tall enough for a few more rides and is hopefully still daring.
T&B