Megosztott hang

My boss hired me for a job I never applied for. Now I'm realizing why. I got an email: You're hired! Start Monday. I never applied anywhere. I was confused. I called the company. They confirmed: You interviewed last week. You signed the contract. I have no memory of this. I checked my calendar. There's a 6-hour gap last Thursday. Completely blank. I went to the office anyway. They showed me my signature on contracts. My handwriting. But I didn't write them. My boss said: Welcome back.