People are paying attention to you a bit more than you expected they would, and I can see it having an effect on you. You didn’t know that former teachers and friends were keeping up with you, or even remembered you. But they did. They do.
Your words, written and spoken, have an effect on others. This is to remind you that no matter what you do, you have to acknowledge the people on the receiving end of your actions. The things you say could either prove valuable or worthless to others. Your goal is to provide meaningful value to others, and that’s it. Going through a 400-word exercise every day may not offer 400 words worth of value every day, but it will make you a better writer and a better thinker. If that’s the case, then you must continue to do it because it will improve your ability to improve the lives of others later in life.