How to pack?

I'm still not sure how I'm expected to fit everything I need for an entire year into less than 100 pounds of luggage.  Besides the fact that there are four seasons in South Korea-meaning I need to pack everything from winter coats, to rain boots, to bikinis-I just plain like clothes.  Choosing what to leave behind will be a long procedure.  There are plenty of websites with suggestions about everything that I'll need, but there's no way to tell until I get there.  Let's be honest, even though I'm starting the process early, I still won't be completely packed when it's time to hit the road in 5 days.

Wish me luck.