A lot of people mock this speech for how awkward and bizarrely mundane it is, but that’s exactly the point. He’s an awkward young adult trying to impress a girl, I’m sure all of us have said similarly strange things when a little nervous. And let’s be honest, someone who grows up to be Darth Vader isn’t going to be the most well adjusted or good at interacting with others.
His hatred of sand makes sense in character too, since he grew up on a planet covered in the stuff. In addition to being corse and irritating, it probably also reminds him at some level of his time living as a slave on a barren planet.
People praise Tarantino’s dialog for how the mundane topics help to ground the characters. Is Anakin’s monologue really that different? I could imagine an alternative universe where Vincent and Jules discuss sand on the way to pick up the briefcase and Anakin tells Padme about his foot massage technique (maybe that would even improve both movies).
Lastly, he’s right. Sand sucks!
I've long though that sub plot could have been improved by having one ten second scene of him practicing those lines he uses on Padme while looking in the mirror