There's a great book by Eric Greitens called Resilience. The chapter on habits is one of my favorites. Here are a few lines from that chapter:
“The direction of a person’s life is shaped not by a single turning point, but by thousands of days, each filled with small, unspectacular decisions and small, unremarkable acts that make us who we are.”
“Your life builds not by dramatic acts, but by accumulation.”
“How many people have put off the necessary, glamorous work of building habits because they spend their lives waiting for an epiphany that never comes? Don’t wait. Don’t wait a single day.”
“For most people engaged in pursuits of excellence, we are not dealing with a single important day of decision. We are instead dealing with days and weeks and months and years of accumulated effort, consistent practice, and wise habit formation.”