The biggest diet/fitness mistakes women make?

Inspired by this article but, to be honest, all I read was the headlines, so it’s not necessary that you read it to answer this question.

What do you think are some myths or misconceptions about weight loss and fitness that seem to be held by women for the most part?

The one that bothers me the most is, “I don’t lift weights because I don’t want to get muscular” or the similar “I lift light weights with high repetitions because I want to ‘tone’ but not ‘bulk’.” The reason these bother me is because they based on the completely false premise that women will become muscular like men if they lift weights. It’s just not true – women aren’t built to bulk like that because that type of muscle growth requires testosterone. This picture illustrates my point nicely. And hey, even the body on the bottom takes more than lifting a few times a week.