I always put a small rock inside my shoe so that I become used to discomfort.
At first it was very bad, I thought about giving up. But now I welcome pain and discomfort.
One of these days I forgot to put a rock in my shoe and I hated the feeling of not having a rock in my shoes. I NEED the discomfort now. I NEED the pain, it stands as a testament to my growth as a man.