Why aren't things the same?

I'll never know what happened,
Blinded by the truth.
Now I stand here waiting,
Thinking of my youth.

What ever happened,
To those joyful days.
Those laughter and those happy tears,
Just went all away.

I feel the raindrops hit,
Stinging me with sadness and pain.
I'm like a lock that lost my key,
Why aren't things the same?