Unreasonable promise..

[Idiom]

While it is an admirable stance to take, all of your promises will inevitably suffer from the same problem. You can promise somebody you'll show up at their house the next day and, for reasons completely out of your control, you will be unable to. The most severe *possibility* of this is that you would simply die beforehand, and your promise would thus be unfulfilled.

If you don't make promises on the basis that you may accidentally break them, then you shouldn't make any promises at all, because there is *always* the possibility something will happen.

Promises are there not to demonstrate that you will never, ever, *ever* break it, no matter what happens (this is unreasonable), but that you will put forth all of your effort to follow through on what you say.