Change my first letter to r, you gain knowledge. Change my third letter to e, you are taking caution. Change my last letter to r, you use one of your senses. Though I may be in the clouds, I am often putting myself in the game.

We are a pair of identical twins who never part, yet we have no heart. We both have necks but never a head, and we’re always empty when you’re in bed.

I could solve this riddle now, but I've got time, I'll do it tomorrow. Or maybe I'll postpone it some more. The day after tomorrow should be OK too.

If you, by any chance, accidentally guess this word, you really made a fortunate discovery.

I dance across a blank white space, colours bloom where I embrace. Bristles at hand, imagination’s rush, what am I that makes the canvas blush?