Simply put we live in a world that is constantly in motion. We are always doing something, and even if we are sitting on a couch doing absolutely nothing, we are probably thinking about doing something. And with this non-stop, ever-changing environment we live in, we find ourselves always saying "yes." It seems like the right thing to do in any given situation. Why would you say "no" when you could be missing out on a huge opportunity? But maybe that's the very reason why you should say no, because you suddenly find yourself overwhelmed by the result of one too many yes's.
Peer pressure is a very real thing, but not just in the way we commonly think of it. It doesn't just come from fellow students or friends. It comes from anywhere really - family, teachers, co-workers. It comes from the collective whole of the human population and our unwritten code of standards. It may even seem like it comes from yourself at times. Whatever the case may be, we feel this pressure to say yes to this job position or this extracurricular activity even though deep down in some subconscious bubble of thought we know we'd rather be saying the opposite.
Contrary to what many may believe, there isn't a set-in-stone way of being a person. Maybe you are someone who is perfectly suited to taking a leadership position in a group, and maybe you are someone who is more comfortable with contributing on the sidelines. One isn't more right than the other; it's just a matter of who you are as a person.
When it comes down to it you aren't obligated to do anything for anyone. Just because you care about someone and they care about you doesn't mean that you have to do whatever they tell you to all the time. You aren't in control of how other people react to your decisions. If someone else doesn't approve of what you say or what you do, then that is their concern, and it shouldn't have to be yours. The only person you can control is yourself and the choices you make. You are the only one in your life who can define those choices.
Life is short, it flies right before our eyes, and that's why it's so important to recognize what truly matters. You can either spend every minute of it worrying over inconsequential things and fall into the fast-paced lifestyle that comes with too many yes's or learn to say yes when it counts, and no when it really doesn't matter and you can live without it. Sometimes it's hard to determine what is and isn't worth following through with, but when you do decide it makes all the difference.