Your brain is a two-way street ... your neurons effect your behavior and your behavior effects your neurons. Every repetition of a thought, no matter what it is, strengthens the synaptic connections in the network of neurons required to think it. The Myelin sheaths (electrical insulation) around the neuronal axons in such network are thickened making them more efficient. This process is actually what happens when we practice ... and practice makes perfect.
Be careful what you perfect.
Quill
I love it when people speak "foreign" hehehehe - True Story! and now that you have given the "solid" explanation it only concretes my opinion! xxx