You may have forgot:
1a. check to see how much time you have
1b. realize it’s too late not to worry about it and too early to start getting ready
1c. get anxious and don’t do anything for a while, repeatedly checking the clock because you’re time blind
1d. get distracted, forget everything
1e. nap
1f. wake up already late, scramble to get dressed properly, go out looking like crap and still anxious
2. Show up 1hr late