Why do we stretch after we wake up up or occasionally at other times?

Why do we stretch after we wake up up or occasionally at other times?
your muscles want to MOVE!! We need to stretch regularly to hold muscles flexible.
I don't know... but it feels sooo apt in the morning.
Stretching also oxygenates your muscles and help get rid of the spend products they've produced during the night.
i hold no idea, i've never stretched after i get up up. i think we only do it to loosen up tbh, if you're tense and that, i construe it's just a raw thing to do to stretch ^^