The last time I weighed myself about 7 years ago, I was 130lbs. Recently weighed myself again and it read 180lbs. I don't feel like my weight has changed much at all in the past 7 years, and I wear some of the same clothes I did back then (as in the exact same pair of jeans or same t-shirt, not just same size).
Has anyone else has had their weight change so much without realising or is it more likely that that one of the scales was wrong?