How come Bill decided to use hammer for "protection"?

Question

The whole plot of Following depends on Bill deciding to take a hammer as his weapon. How did Cobb make sure he will do that?

Why on earth would Bill take that hammer to Blonde's house afterwards and even put it there?

Answer 1

1. 00:22:17

Surprisingly enough, I thought you might be able to give me some advice.

- Steel whip. Nunchucks, they're all right. Tools are good, sharpened screwdriver, hammer, chisel

- "Hammer"?

- Yeah. Medium size. Good rubber grip. It's very nasty. If you get a claw hammer, you can pry doors with it. Slip it into the back of your waistband, you're set.

2. 00:34:31

there were a couple of hammers in the old house, influencing bill's sub-conscious

3. 00:36:20

The blonde tells him the story of the bald killing someone using hammer

They didn't like this very much, so they got a hammer. They held him down, and they smashed every single one of his fingers. And then they smashed his skull.

Please note that she did not have to tell him these at all. If she said it, she meant to say it. She probably was trying to put it in his sub-conscious.