I knew I was registering the colour blue, but it was spitting and fizzing like an erratic sparkler. The entire surface of the bin was an unstable, frothing mass. Mesmerised, I limped right up to the bin and reached out my right hand. I’m still not sure why I felt compelled to touch the bin, but I did. Feeling the hard plastic, I spoke the word “blue” out loud. The sparkling stopped immediately, and the bin became a flat, rather lifeless blue. Cautiously I stepped back, but to my astonishment, the blue fizzing started up again.

I'm fascinated by synaesthesia.