Your story (such as it is) gives no clue as to what the pebble is, or the pond, or anything else.
And YES, I can disagree, if there is reason to, or I can offer an agreement to what is said... much like saying Amen after a good point in a sermon.
As to my alternative to the statement:”You have no control over the things that are done to you, but only the things you do about it.”????
You cetainly have control over where you put your time. If you hate barfights, stay out of bars.