Theta is an important and interesting biological signature for active movement, at least in the rat hippocampal formation. Theta was long predicted to be present in human brain, because it had been observed in mobile rats,9 but similar experiments could not be conducted on humans - finding theta in humans remained for special neurosurgical circumstances to arise. Standard methods involve recording the EEG signal present at the scalp in humans, but the location of the hippocampal formation means that detecting hippocampal theta is extremely difficult: it might be sitting in there somewhere, but finding theta, if it is present, is a challenge.
The latest generation of miniaturised neurophysiological recording systems, however, allow just this possibility in human patients using electrodes implanted for the purpose of assessing them for epilepsy surgery.10 What the study shows is that theta is indeed present, and to all intents and purposes, it differs little from theta found in the freely moving and exploring rat. Humans, like all other mammalian species tested, express theta in the hippocampal formation when they are walking about the environment. In other words, theta is something of a biological universal; it is a signal, conserved across species, that the brain is engaged in active exploration and movement within an environment.
Instead, imagine a river with lots of tributaries. Even if there is little water in a few of them, there will still be a considerable flow into the river. Multiple incomes allow one area to carry another. Several small streams of income will give more security than one large one. When you have this, you will worry less.
The life that you lead may have financial constraints. These will either be reminding you to spend less and save more, or it is reminding you that it is time to clean up your debts. Student loans, graduate loans and the like are a way of saying, "I have money earning potential in the long term". Forget about them short term. When you do come to pay them back, don't rush. Have a budget that is comfortable and avoid making debts to pay off debts.