I don't feel frightened by not knowing things.

All things are made of atoms - little particles that move around in perpetual motion, attracting each other when they are a little distance apart, but repelling upon being squeezed into one another. In that one sentence, you will see, there is an enormous amount of information about the world, if just a little imagination and thinking are applied.

It's because somebody knows something about it that we can't talk about physics. It's the things that nobody knows anything about we can discuss.

The exception tests the rule.

The first principle is that you must not fool yourself and you are the easiest person to fool.

Strange! I don't understand how it is that we can write mathematical expressions and calculate what the thing is going to do without being able to picture it.

As you know, a theory in physics is not useful unless it is able to predict underlined effects which we would otherwise expect.