Do You Go up the Stairs and Count the Steps?

"When you go up the stairs, do you count the steps?" When his friend asked this strange question on the phone, Chen Mo just felt that he had lost his head after working overtime. Until the next day, his friend was found dead mysteriously in the stairwell of the company - surveillance showed that he had been climbing alone on the stairs to the 12th floor all night. The medical examiner said he was exhausted to death. Chen Mo, who took over his friend's belongings, saw a line of blood scrawled in his work notes: "Never count the 13th step between the 12th and 13th floors..." Chen Mo didn't take it seriously until he returned home late at night. He walked up the stairs as usual. By some strange coincidence, he started counting: "1, 2, 3...11, 12..." The footsteps stopped and he stood at the door of his home, cold sweat instantly soaking his shirt. The old building he lives in has only 11 floors. So... Dear readers, now you close your eyes and recall, have you ever counted the steps when you go up the stairs?