I have heard of people having great difficulty in giving up coffee, but I have never had any sort of withdrawl myself.
There have been times when we have been on vacation where it simply wasn't possible to get a cup in the morning.
Didn't bother me at all.
There are times when we run out, because I've forgotten to buy coffee, and I do without the next morning.
My wife, incidentally, is a tea drinker, and never drinks coffee.
It doesn't cause me any problems.
I guess that withdrawl is real for most, however.