You are supposed to get training when dealing with anything different and dangerous. Say you rock climb for the first time... and the instructor talks to you fo

You are supposed to get training when dealing with anything different and dangerous. Say you rock climb for the first time... and the instructor talks to you for 10 minutes about various stuff and somewhere in the middle he says: "and make sure to check that you can't see 'danger' written on the clasp of the harness, you may fall if it's not secured properly". You have lots of stuff to think about... your posture, the grip, the path you want to take... in a group of 10 people, is it really that unlikely that one will simply forget? That's why the first couple of times somebody more experienced will check everything about your harness.