Happiness is very personal and very subjective. It is related to material and environment, but more importantly depends on one's mentality. The happiness of others may not be their own happiness; their happiness may not be the happiness of others. Telling your happiness to others may not bring happiness to others; others telling happiness to themselves may not bring happiness to themselves. Based on the above statement, which of the following can be derived? ['The happiness of others may bring happiness.', 'Your own happiness may be the happiness of others.', 'The happiness of others may not be their own.', 'Your own happiness may bring happiness to others.']