You can actually shape your mind with shamatha, or the discipline of meditation. Your mind can be shaped like Play-Doh: you can make it into any shape you like. If you want to make your mind into a horse, an elephant, a giraffe, a square, a triangle, or just a round ball, you are free to do so. You can reshape your mind according to the discipline of mindfulness.
From “Antidotes to the Obstacles of Shamatha” in The Path of Individual Liberation: Volume One of The Profound Treasury of the Ocean of Dharma by Chögyam Trungpa, page 253