I think an interesting thing that Moxie touches on tangentially, is that life does not go as planned; things break. Everything breaks, in fact. Learning to recover from failure is often more important (and personally rewarding) than learning to use the tool in the first place. You may choose to get better tools, but given time and use, these too will eventually fail.
Operating with the understanding that everything fails, allows us to be more flexible and pragmatic in our decisions and planning. Assuming that something will never fail only ensures that a disaster will eventually happen, and that you will be unequipped to handle it.