Every bad time has good times just in front of it. We just need to wait for it to happen.

We're all awaiting our own winds to pick us up when we're down, and sometimes you need to wait for it, but no matter how hard it gets it will still come.

People can feel dead and completely hopeless, without knowing that their Western Wind is going to pick them up and give them new life.

Poses the question: why read or learn if you'll only end up forgetting?

These are two things that people say you "can never forget," but even so, they're still not immune to the passage of time and the aging of a brain.

Greek mythology; the river Lethe in the Underworld, the river of forgetfulness. When people died and went to the Underworld, their souls had to drink from it in order to forget their past lives and be reincarnated

Reminds me of how right now there's less pollution and animals are returning to places that got too dirty for them or are coming out into vacated public places when people aren't there; in this poem it's before anyone is awake and before people start affecting the land that it is beautiful.

This wording ("make up") implies that the speaker may not believe in Heaven and consider it to be created by those who benefit from people believing in it (i.e. priests, etc.), and those who believe in it only do so because their time on Earth is spent in woe.

The entire poem makes references to fire (specifically this line stands out) and makes it seem as if the tiger was created in Hell, which is why there is no confirmation as to whether or not it was made by God.