<p>Honestly, I don’t think Caltech is a great fit for the OP. </p>
<p>The sort of person who does well at Caltech has to enjoy regular and long bouts of intense immersion in science. People do hang out and have fun in the in-between times. It helps to be introverted I think. I encourage you to find out more about Caltech, though. This is just my impression from what you wrote.</p>
<p>Also, how do you feel about theory and physics in particular? You probably would be doing more theory at Caltech just taking the core than you would as a physics major at UCLA.</p>