Your body ( blood flow mainly) has to adjust to the upright position and there are many mechanisms for it to do so........mainly in the blood vessels.
As you get older, your blood vessels get a bit "thickened" and they are slow to adopt to the "upright position."
Bazille, that thing you're bending down to put in the cabinet. It's not a bottle of rum after taking a few snorts is it? That could account for the disorientated feeling:)