Rain - because it doesn't happen enough where I live.
The smell of the beach - I grew up living on the beachfront, good times.
And freshly cut grass/lawn - This smell instantly takes me back to my younger days playing junior sport, smelling this is like a time machine, I can see things I'd long forgotten, remember the sporting ovals I played at..good times
Hahaha! I know! Weird eh? When I was a kid and my parents would start the car in the morning to warm it up, I'd stand behind the car smelling the exhaust, I loved it! They did not share my enthusiasm lol. And I did sniff a few too many markers when I was younger. I was pretty dumb