You can smell autumn in August. Some don't believe it, but you can.
And when you're out playing Hide-and-Go-Seek-Tag with the siblings, you're sitting in the tall grass, listening to the wind and watching the world just toss and turn around you, and you smell the autumn in the cool wind, that's when you really start to believe it. Even more so when it rains and the chill in the morning wraps you up, and you go sift through your coat rack for a hoodie.
Some just believe in things you can see. Some just believe in things proven by scientists. Some don't believe anything at all. But those people don't usually believe in fairies, either. I'm inclined to say what Anne said to Marilla when they say that autumn is not painted on leaves by fairies, or that you can smell autumn on the wind or see it in clouds:
"How much you miss."
Not everything is science. Not everything can be explained. And not everything is believed in with a full understanding. Maybe because, with some things, understanding isn't the key priority. Just believing is enough. Like God.
There's my memory for the day.