Heroic Effort vs Consistent Effort
In our meditation practice, we may put too much emphasis on occasional huge expense of effort, and underestimate the effects of small but persistent effort.
Just to let go of a little grumpy thought doesn't seem much. Just to think once: “May all beings be happy and at ease” looks like nothing.
But doing exactly these 'small', 'little' things consistantly, continuously over hours, days, years and decades is sufficient to dramatically change our character, attain samādhi, and carry us most of the way to Nibbāna.