The 83-year-old British writer and director, who was diagnosed 18 months ago, spoke for the first time about his condition at a special event hosted by Britain's Alzheimer's Society on Thursday (28Jun12).
Anderson recalled how he was initially convinced there was nothing wrong with him when his partner Mary first pointed out recurring symptoms.
Anderson tells the BBC, "I don't think I realised at all. It was my wife Mary who began to notice that I would do something quite daft like putting the kettle in the sink and waiting for it to boil.
"Finally I was persuaded to go and see the doctor and eventually I was confronted with the traditional test - a piece of paper with drawings on it, taking a pencil and copying them. I thought, 'Why are they doing this? A child could do this.' But when I started to copy the drawings, that wasn't the case. I started to get in a muddle. That's when I began to realise that there was something wrong."
The marionette master admits the "bitterest blow of all" was being told he could no longer drive his car.
He adds, "That virtually took away my freedom. It meant that I couldn't go to Pinewood studios where I worked, and this depressed me enormously because my film work was my life. Suddenly my life was cut off. Since I've had Alzheimer's I've realised how debilitating it is. It can affect your life in so many ways that you don't think about."
Anderson has joined Alzheimer's Society ambassador Carey Mulligan in encouraging Britons to sign up for the charity's fundraising Memory Walks, which will take place throughout England, Wales and Northern Ireland this autumn (12).