Why is it when i go to sleep late, I wake up 2 hours later still feeling I'!

This has happened a lot of times to me... One time i fell asleep while i was watching a movie and when i woke up, i was blinking rapidly and it didn't feel i was out of my dream yet because i was talking about what happened in the past when i don't notice. let me give you an example if you don't understand.. I went to a party and i had to go to the train station, and i was using this machine to get a ticket so i could pass... there you go. so when i was talking about the past, the next morning my brother said that i was saying "wheres the machine?" and he said "what machine?" then again i said "The machine!" i never had a clue that i did that. Also i remember when i was about seven, i woke up at about 11pm to go and have a shower, i didn't know what i was doing . I wasn't sure if i wasn't awake properly or if i was sleep walking... Okay so this doesn't happen every night, It only happens on weekends at about 9pm to 11pm while sleeping while watching something.... Please if you do understand, answer because i'm not sure what is wrong with me. my parents don't know why it happens either... Thanks :) Also i had no clue and i didn't remember what happened that night until someone told me.