Greetings! So, a friend of mine asked me the other day why I have so much stuff on my key chain. Good point but there is a quick answer.
In many cases, you will have only three things on you: clothes, wallet, and keys. You change clothes every day and sometimes you do not need your wallet. So, most important stuff that can help you in many situations better be attached to your keys. I have a snap key chain which can be separated into car keys and house keys. There is a multi-tool, small knife, and tiny but powerful light. The set proved its worth few times. 🙂