The liberating insight is that the slight irritation caused by someone slow in line ahead of you,
or an itch on your forehead, and the massive sadness caused by a girl who broke your heart or a loved one dying are different only in quantity, not quality.
Both are basically impermanent. Both dissolve with awareness.
Like a clean floor with a few cookie crumbs on it, and a floor covered with mud and food crumbs, the cleaning process is the same in both cases. The guarantee of success is the same: The more you have cleaned, and the less dirt you have added, the cleaner the floor is.