Marcus suggests that true peace of mind arises from focusing on our actions rather than being swayed by ambition or self-indulgence.

Ask yourself: How often do you find your mood or sense of self-worth dictated by the opinions of others or by circumstances outside of your control? Do you feel incessantly driven by an ambition reliant on the praise or acknowledgement of peers? Or, distracted by the self-indulgence of becoming engrossed with the happenings in your own life that you forget to act?

Marcus encourages real "sanity"—to tether our happiness to our own deeds instead. That's where true control lies, in the choices we make and actions we take every day. No one, no external situation, can take that control from us.

Start today, detach from the tyranny of others' opinions and fortuitous elements of life, latch onto the grounding anchor of your own actions and find sanity.