Recursive Inventor Paradox

Imagine you are going to invent a device that allows you to time travel forward and backward in time. If you are successful, you promise to yourself that you will deliver the device to your past self (now). This means if you are in fact capable of building such a device you will automatically receive said device from your future self immediately.

If everyone that is born has this thought and promises to follow through with delivery of such a device if they are capable it would be the most efficient way of inventing such a device.