I find that, as I get older, jet-lag gets worse. Though it never bothers me domestically, tranPac and transAtlantic, I can get it really bad. For me, going east is the worst -- westbound not too bad. Also, the longer I spend in the "foreign" time zone, the worse I'm jetlagged when I get home.
I returned from three weeks in Asia two weeks ago. It's only the last day or two where I've begun to feel normal and sleep through the night.