What's "close reminder" mean?
Answer from a Native speaker
A "close reminder" is something that causes you to remember something because of a "close call!" And a "close call" is when something bad, dangerous, or an accident almost happens. I would say that "close call" is more common than "close reminder," though. Ex: That car stopping quickly in front of us is a close reminder to always wear a seatbelt! Ex: We had a few good close reminders while rock climbing to watch where we put our feet. Ex: That was a close call. I thought I was going to be late for the meeting.