Overpacking

I don't know what it is but I am terrible at overpacking. I always try to pack for every eventuality as you can't always predict the weather or the outcome of the trip. It doesn't matter how well I think I've packed, there may be times when that one essential item is left behind. In the rush of packing I usually forget something - Just have to hope it's nothing too important as you can pick up replacement bits from the shops.
Making sure you've got everything you need is all well and good until it comes to carrying the case and realising you probably didn't need all these items after all. After this the day is filled with finding the nearest lift or escalator, and using arm muscles you didn't realise you had.