It's bad to wait until the last minute to leave.
John is at home getting ready for a job interview.
John wants to get a job.
John leaves an hour early for the job interview and gets there in time despite traffic.
John does not leave his house until 15 minutes before the interview because it is only a 10-minute drive away.
John gets the job.
John gets stuck in traffic, is late for the interview, and does not get the job as a result.