...because you're scared?
...because of what other people might think of you?
...because you might not do it right the first time (or the second, or maybe even the third)?
...because it's not the "normal" or "accepted" thing to do?
...because of the other becauses that are keeping you from doing it?
You can live your life and make your decisions based on fear, others' expectations, or accepting what is. Or you can take risks, do things differently, and pursue what could be.
Sometimes logic, conventional wisdom, and common sense are what keep us from doing extraordinary things. The greatest inventions, insights, and innovations in history didn't come from playing it safe or maintaining the status quo.