To a Dragon with a long lifespan, several decades are just a trivial matter. It's known that Dragons will seek revenge long after being offended or defeated by humanoids, only to find that the ones who wronged or defeated them are already dead, thus they vent their anger on the descendants or hometowns of those humanoids, causing immense harm.
I've been transported here for several decades now, longer than I lived on Earth, directly leading many of Leon's values to become alienated and distorted, but it doesn't stop him from considering thirty-five years a long time, unless there's a deep grudge, there's no need to remember for that long.
A man in luxurious clothing came with assassins seeking revenge. To Leon, this behavior seemed quite petty; even if surrounded, he just found it amusing, saying: "I'm in a pretty good mood now, I can overlook all this if you disperse now, and I'll pretend nothing happened."