I believe the song is about dreaming as a young child, and thinking about how amazing growing up would be, then reality (or the hornet) stings you, and you start to become less optimistic as your problems or "rain" fall on you in real time, and you have no way to deal with a lot of them.
I believe the song is about dreaming as a young child, and thinking about how amazing growing up would be, then reality (or the hornet) stings you, and you start to become less optimistic as your problems or "rain" fall on you in real time, and you have no way to deal with a lot of them.