All our life is sown with tiny thorns that produce in our hearts a thousand involuntary movements of hatred, envy, fear, impatience, a thousand little fleeting disappointments, a thousand slight worries, a thousand disturbances that momentarily alter our peace of soul. For example, a word escapes that should not have been spoken. Or someone utters another that offends us. A child inconveniences you. A bore stops you. You don't like the weather. Your work is not going according to plan. A piece of furniture is broken. A dress is torn.
I know that these are not occasions for practicing very heroic virtue. But they would definitely be enough to acquire it if we really wished to.