discipline is only exhaustible if it's not part of your identity
if pushing through discomfort is unusual in your day to day of course you're gonna get tired & burn out
but if you just see yourself as the person who does that then it comes an infinite resource
Mac changed everything when it was introduced 40 years ago, and through the years it has done so again and again and again. Today’s Mac lineup is the best in the history of the personal computer, and it’s built on decades of revolutionary innovation. Happy birthday Mac!