The Hubble Blew My Mind
Secondly - and most importantly - my daughter told me the answer. This might sound weird if you don't have kids - but for your kid to know the answer to something you genuinely don't know - that's really special for them.
All of this from a little black piece of glass and metal. I know I'll be called a fan-boy for this, but yes, that was magical.
A short real story when pieces of modern technology play together. Do you still let yourself be amazed?