40 and the Great Sandal Exchange phenomenon

Singapore is 40 today...

Going to the parade today. That means I am going 3 years in the running. Actually this year I didn't get the tix but my best fren did and he is bringing me along.
A few months ago I put my sandal outside the house in the shoe rack and didn't bring it in. The next day I found that someone took it and replaced it with another. Strange but it did happen. The one that he, she, it, whoever gave me was quite good actually. I wore it until one day this kid lost his slippers in the mosque and I passed the sandals to him. I went home barefooted that night. I bought a new one and recently and I forgot to put it inside and again it was replaced. Who is it that is doing this? A kid? A man? A nut? Maybe I will never know.