Like a marathon in which the finish line keeps moving backwards, the modern email inbox is an unwinnable game because it's infinite. A simple trick for Gmail users can fix this, turning the inbox into a finite, and therefore winnable game.
The following link is a bookmarklet. To save it in Chrome, drag the link to your bookmarks bar.
When you click the bookmarklet, it loads the Gmail inbox with a search that contains emails only from yesterday and earlier. This means that it's possible to empty your inbox and it will stay empty for the rest of the day!
This makes emptying my inbox a winnable game which I make a habit of playing every morning. For the rest of the day I am productive, not interrupting my workflow to check my inbox and relaxed in the knowledge that I won't need to play the inbox game again until tomorrow.
Bonus: You may find that this bookmarklet works well with the Chrome extension Unread message count hider for Gmail™.