Jet lag

Is it possible for me to still suffer from jet lag?

Last night when I was online two of my friends were online at the same time. So I chatted until an hour or so past my new bedtime. I thought it would be okay since I didn't have to get up early this morning. And indeed, this morning I slept in a little.

Man, am I tired now! It's effort just to keep my eyes open. I still have some work to do before I can go home, but it feels almost impossible to concentrate.