Wise advice on acceptance

Shut the iron doors on the past and the future, live in the present - Dale Carnegie
The core message is radical mental hygiene: deliberately and forcefully sealing off the mental energy drains of past regrets and future worries so you can invest that energy fully in the present.

What focus means

Live in day tight compartments - Dale Carnegie
It means to deliberately confine your focus and energy to the present 24-hour period, sealing it off from past regrets and future anxieties like a watertight compartment on a ship.