That is what most students believe. But the reality is that this is a terrible approach to try and get accepted into a highly competitive college.
The most selective colleges want well rounded classes. They want students involved in volleyball or who play the flute or who love doing research. But the strongest students will be those that have a passion for one or two of things.
It doesn’t matter what your passion is but the more you can demonstrate it, the better. If you have a passion for the tuba, play in your local school band and orchestra, start a jazz band with some of your friends, volunteer to play the tuba at local nursing homes or help teach younger students how to play the tuba. When colleges look at your application you will be the tuba kid.
This doesn’t mean that you can’t get involved in activities outside your passion. But, the more that a selective college can look at your application and say “this student clearly has a passion for x”, the stronger the applicant you will be.
So, what is your passion?