Is Derek your husband, lol? I suffer from two of the problems - one is the stress of actually preparing for packing, and the other is wanting to take too much.
For the first I have found it helpful to:
have a permanent list available, plus a little list for last minute additions;
choosing stuff to take gradually over a couple of weeks, as I have a spare room with a rail they can be hung on;
wash my washbag on return and repack it with travel toiletries and putting little note in for anything last minute or needing purchasing.
All this sounds time consuming, but it doesnt actually take any longer.
For the second:
While it would be nice if I was small enough to fit into skimpy clothing, and if I felt I could actually walk around in sandals and bare feet for two minutes without getting a blister, and if I could be sure I wouldn't get a lasting heat rash that causes my dresses to stay unworn, and if I only went places with completely settled weather.......then i would go just with designer hand luggage.
As it is I just pile it all in up to the weight allowance, and make DH push around my 23kg suitcase, then I can choose according to the weather when we get there.
However, I have enjoyed reading this thread, and hope the poster picks up a section of tips from all our replies