How do they do it? I dont know.
I continually find myself alone within a supermarket. I swear i had a wife with me when i entered but within seconds she had disappeared into the horrific world of consumerism.
Walking up and down the aisles, she was no-where to be seen. I actually ended up attempting to 'trick' her into appearing by randomly increasing my walking speed so that if wifey was mirroring my every step and hiding between rows when i passed i could catch her out. -- yes, shopping makes me crazy.