Why do Koreans do things at the last minute?

This is by no means a form of racism or slander to Korean people or their culture. However, from my own personal experience working I have noticed that Koreans have a tendency of doing things at the last minute. Examples such as having materials ready, or notifying people meeting/events with little advanced notice. I am just curious if it's a cultural thing. If so, why? Has anyone else experienced this? I have experienced the mad scramble many times.