What is best way of reading that last long in the mind?

By connecting the new knowledge to things you already know.

Take history for instance, if you learn this as an isolated series of "bubbles" of important events, you don't retain much beyond a memorized list of wars and kings. Howver, if you see it as a series of connected stories, a longer narrative, you do.

Memorizing he periodic table? boredom

Realizing that the periodic table is actually organized around the number of electrons in the atom's shells? Just the type of knowledge that turns a boring table into a tool you routinely use when working out chemistry problems.