My theory is that luggage mysteriously expands to fill the space available, and, there is never enough space available
The lovely Lady Budster has many fine qualities; however packing light is not one of them. Even for just a weekend, we seem to carry ridiculous amounts. SBM is my witness to this, when he offered to carry tlLB's case to the car at the Cottage In The Wood, last year.

However, time has taught me that it is best not to argue.
The notice below, I am sure, may be relevant to many TMers!