toddler to teenager

i remember being a teenager & spending countless hours hanging out in my room... talking on the phone, listening to music, or just chillin. well, it seems my child thinks he is an independent teenager. his latest thing is to go in his room, close the door & hang out. yesterday i tried to go in & he quickly said, "get out, my bed". OH REALLY! then he proceeded to push me out the door & close it behind me. OUCH! i guess i was intruding on him playing with his backpack full of rocks! then today he went in again... this time when i tried to go in he was laying on the floor in front of the door with his feet up against the door. he was just hangin out. GEEZ. has it already come to this!??! :)