You Can Influence Your Surroundings
You can build up your strength to the point where you are not influenced by your surroundings; in fact, you can influence the surroundings instead. You can change the environment if you have the strength of mind; but even if your mind isn’t that strong, you can still have the strength not to be affected by the environment.
Learning not to be affected is an important step. If you are influenced by a situation, how can you change it? If fifteen people are crying and you go there and join them in the crying, you have simply added one more miserable person; you have not done anything to benefit people. Instead, if you are really strong and can maintain your own equanimity, all the fifteen people will be benefited by your strength.