Old-timey ‘high-wheeler’ bicycles were also known as ‘penny farthings’, because people thought they looked like the largest (penny) and smallest (farthing) coins of the day rolling after each other. The reason one wheel was oversized was that they had no gears or chains, and the only way to make them go faster was by having a big front wheel. 
Curiosity is fueled by what you already know. You’re far more likely to be curious of the things you already know a little about than you are of something you know a lot about or know absolutely nothing about. (, )