Why does Victor Frankenstein remember the thunderstorm from his childhood so vividly?

The thunderstorm and the destruction of the tree was Victor's first experience with electricity. Although Victor had previously been exposed to electricity, this is the incident that sparked his real interest.

When I was about fifteen years old we had retired to our house near Belrive, when we witnessed a most violent and terrible thunderstorm. It advanced from behind the mountains of Jura, and the thunder burst at once with frightful loudness from various quarters of the heavens. I remained, while the storm lasted, watching its progress with curiosity and delight. 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 reduced to thin ribbons of wood. I never beheld anything so utterly destroyed.