Why does Frankenstein remember the thunderstorm so vividly?

Frankenstein vividly remembers the destruction of the tree by lightning... the effects of electricity.

As I stood at the door, on a sudden I beheld a stream of fire issue from an old and beautiful oak which stood about twenty yards from our house; and so soon as the dazzling light vanished, the oak had disappeared, and nothing remained but a blasted stump. When we visited it the next morning, we found the tree shattered in a singular manner. It was not splintered by the shock, but entirely re- duced to thin ribbons of wood. I never beheld anything so utterly destroyed.