You hired someone to install cameras in your house because you felt like you had a stalker. When the technician knocked on the door, you opened it

You both greeted to each other as you kindly let him in your house

"So, where do you want to put the cameras?"

"We can start with my room" you answered

he nodded and walked right into the direction of your bedroom, then you froze

you lived in a very huge mansion

"wait a minute.. How did you know where my room is?"

"oops!" he chuckle