They can be Happy They can be birth. They can be dark. They can be cake. They can even be ones that will go down in infamy. But they come one at a time and you never get them back, so don’t waste them.

The longer I am, the better the experience. What am I?

Usually seen in parks Popular with kids In verb form, it just moves like a pendulum

Built to break what can’t be killed, I face the rage, you feel the still. Neither sea nor land I stand, A fist of stone with open hand.

First word: big eyed, grey and green. With the long key in between. Last word: cut and glue together, make a paper stream.