After a while I stopped thinking about him so he will cease to exist. I tried to erase him from my mind. He started to appear in my dreams. I started thinking maybe this is more than a tulpa, thoughtform, construct. Maybe he is something much more than my understanding. One day, I went to use the bathroom. The bathroom had two doors. The first door I NEVER CLOSE. The second door i do. When I used the bathroom, I heard a weird sound. The reason for it being weird is that i was the only one in that secotion of the house. I told myself maybe its slendy but i was only joking. I opened the second door and the first door was completly closed. I opened the first door and there was nobody. I asked my mom did she do it. She said no...

My understanding of Slenderman:

Created as an internet meme, he now is thought about and read about so much every day he will never cease to exist unless the story, pictures and meme are wiped from the internet, then every single person who knows about him (at least in the thousands) would need their minds re-written.

No, he's never leaving this plane of existence. Ever. I mean, how many Telepaths would you need for what I described above?