Car boot sales. I used to go because I loved rooting through all the boxes and finding bargains. I was never looking to buy anything in particular, but I always seemed to come home with plenty of things.
I did ask myself questions occasionally when I came home and put my new acquisitions straight in the loft or garage. However, I decided I had to steer clear of car boots when I realised I was taking those things up to the charity shop several months later to make space for more!