Thin and flimsy? You should be able to get a knot so tight a mouse couldn't stick its little mouse pecker in there.
And you call that a dimple? Dimple before you tighten, when you've got enough room on top of the knot to slide your finger through, just like your papa taught you.
But maybe he didn't teach you too good. Papa Rudals done let me down. Let me take you aside son, and show you the stuff knots are made of. I'm spoilering this image, because this knot is plain and simple fuckable. This is the shit that causes popes to retire. It will grant you a seam splitting erection.
Warning: Spoiler! (Click to show)
Now get a napkin, clean off your pants, head to the bathroom, and make me proud.