Supermarket cashiers would stare at me blankly when I used unnatural textbook phrases. At Shinjuku station I resorted to hang gestures and air drawings to the metro police when I had used the wrong metro ticket when making a transfer from the Odakyu Line to Tokyo Metro. I was publicly reprimanded at work for not contacting the office when our train was delayed after having to make an emergency stop while underground. My vocabulary study lists didn't include "no cellphone reception underground".
Looking back on my experience as a whole, I had a tough time adjusting to the isolation and totality of the unfamiliar. The friends I met in Tokyo helped me to take everything less seriously.