If you copy others' work, it will not affect you personally. It will not change your life, it will not make you someone different if you just took a couple of ideas from the work of someone else. However, we are prone to a more dangerous type of copying...
When you see five ways to do something, you usually think you have to pick one of them and follow it. Most of the time all of these ways are relatively obvious and you learned them from someone's experience. So when you follow one of these paths, you are copying someone's way of doing this thing. And what if “this thing” is your life?
There is nothing wrong in copying someone's way of living, but you have to be conscious that always there is one way that nobody else took. Imagine someone you think is successful in life. Did they follow the path that everybody else is following? Did they listen to everything society told them to do? There is a high chance the answer to these questions will be “no”. Now ask yourself the same questions.
If society can show you the way, then this way is visible to everyone else. Then everyone will be able to follow that way and achieve the same results as you. Are people who you admire or consider your heroes achieving the things that other people do? Or are they doing something above that, something that nobody else is doing? They should be special in some way, otherwise it doesn't make sense. And this speciality isn't achieved by following the commonly known path.