Why does everything want to go to a lower energy state?

We often says everything tends to go to a lower energy state. When we say this we intuitively justify it by our own actions. :) But microscopic particles like electrons supposedly do not have intelligence, how do they 'know' there is a lower energy state? For example, lets assume a Hydrogen atom with its electron in an excited state. You will tell me that the electron will jump down to the ground state and emit limit corresponding to the energy difference. But how did the electron 'know' that there was a lower energy state? Solving Schrodinger equation for the excited electron will give you that the electron will stay in its excited state for eternity. So what is the catch?

NB: People who know many body theory will probably tell me that the electron and photon comprise a system and there is no concept of 'knowing'. But lets consider an isolated box containing the excited hydrogen atom only. Now how can the electron and photon be a system?