From Bhagvat-Gita Chapter II, Verse 5:
Suppose while we are driving on a crowded lane, we notice someone driving wildly on an adjacent lane. If we get angry at their irresponsible driving and start gesticulating and yelling at them, we may run into danger on our own lane.
We need to keep small things small. But how do small things become big in the first place?
To understand, let’s compare our mind with a computer screen. There, while we are focusing on one thing, many other thoughts pop up. If we uncritically dwell on such stray thoughts, we get distracted, sometimes distressingly or even dangerously distracted.
However, keeping small things small is not easy. Why not? Because the pop-ups in the mind frequently don’t come with any dismiss buttons – we can’t easily drive thoughts out of our mind.
What, then, can we do about such stray thoughts? Neglect them. To neglect small things, we need some big thing to attend to, remind ourselves of that thing’s importance, and direct our attention toward it.
A pertinent psychological principle is this: the more we dwell on anything, be it a small thing or a big thing, the bigger it becomes in our consciousness, thereby making other things small. If we focus on keeping big things big, small things concomitantly stay small. Even if some small thing remains in our mind, it can’t distract us.
It’s easy to see all of the above makes sense and is secular, applicable to what one considers as big in one’s life. Of course Gita has its own assertions on the subject of what’s big and what’s small in life.