一道曾经的英语听力题的疑问

一道曾经的英语听力题的疑问
W:Hello This is Dr.Fray'office We are calling you to reminder you of your 4:15 appointment tomorrow.
M:Oh ,thanks It's a good thing that you called.I thought it was 4:15 today.
Q:What do we learn from the question?
The man was confused about the date of the appointment.
他怎么会confused?他很清楚日期,只不过不正确,但没有迷惑啊