No matter how little or how much you use me, you change me every month. What am I?

I am first found in caves, now prolific online; I am a depiction, a drawing, a symbol, or sign. I will convey whichever mood you could wish; or for that matter, a fist, flask, or fish. What am I?

The first person saw the bridge step on it and crossed,
the second person saw the bridge did not step on it but crossed,
the third person did not see the bridge did not step on it but crossed.
Who are these people?

What is in seasons, seconds, centuries and minutes but not in decades, years or days?

Spelt forwards I’m what you do every day, spelled backwards I’m something you hate. What am I?

I welcome the day with a show of light, I stealthily came here in the night. I bathe the earthy stuff at dawn, But by noon, alas! I'm gone.

You measure my life in hours
I serve you by expiring
I vanish faster when I am thin
and slower when I am thick
The wind is my energy
What am I?

I’m tall when I’m young, and I’m short when I’m old. What am I?

I am sometimes honest
Sometimes dishonest
I can be sweet and also bitter
I can hurt you real bad and
also make u smile and blush ☺️
What am I?

I make a loud sound when I’m changing. When I do change, I get bigger but weigh less. What am I?