Are there people that chase rainbows like storm chasers/tornado chasers? because I would watch a show about that.

The trick is, you can never actually get closer to a rainbow. The way the light is refracted by water droplets causes it to appear in the distance, but that distance will remain fixed even as you move. There's nothing to chase, they will remain forever elusive.

Tricksy leprechauns actually found a really good hiding place for their gold.