Amazing experience, i love this part where you
said

The sunshine lying on the ground gave me a strange comfort hard to tell about.
It suddenly brought me to my childhood.
I remember my childhood. At that time I was happy just for looking at the sunshine sitting on the wooden floor with my grandma. Yes, It was the autumn. Today's sunshine was as same as the sunshine what I saw in my childhood.
The feeling of happiness had spread into my heart smoothly and slowly.
I remember the cat snoozing under the sunshine of the autumn until now.

So lovely