Why am I tired but awake again shortly afterwards?

I went to bed last night around 9pm and watched Netflix. So from 11pm I was tired and actually wanted to go to sleep. Shortly afterwards I was wide awake again and spoke on the phone with a friend until 3 a.m.

This morning I woke up around 8.30 a.m.

Why am I tired but suddenly awake again?

Because you are human ^^

Yes, but how can I be tired and wake up shortly afterwards?

This could have to do with the heat in the summer, which is tired but you can't really sleep with the heat. I was also tired on Monday.

That comes from not going to bed regularly, which means you go to bed at 10:30 p.m. And get up in 7-8.