I gave a gist of it.
So the story goes this way when Lord Ram and his army had been fighting with Ravana’s army for many days. Many of the warriors were wounded and on one such day, Lakshman (Ram’s younger brother) was deeply wounded by an arrow — and the only way to save his life was through a life-restoring herb, Sanjeevani — found on a mountain called Dronagiri. Now, Hanuman had boon/ability to fly off and hence took the responsibility. He had to be back with the herb as soon as possible. There was some restriction.
When he reaches the mountain, he struggled to identify the life-saving herb — And so takes the entire mountain with his strength.This helped Lakshman to heal his wounds and so do other warriors. So, ultimately a devotion towards Lord Ram. This version of the story is the one which came down to me over the years — funny it is, such stories get evolved, some things are added and few others are lost in the way.
I like that word meek. I struggled to find an alternative strong word for being submissive — thank you. :D