I completely believe in equality of the sexes, but never sure if I really want to label myself as a 'feminist' - I don't really like labels, but if I called myself anything it would be an 'egalitarian'.
Firstly, although I agree with the definition of feminism, I don't like a lot of modern western feminism. I feel it often focuses on things that aren't really big issues (like man spreading or something), but ignores a lot of bigger issues in other countries - such as girls unable to go to school or forced into marriage. Of course I'm not saying that feminists don't care about these issues, I just wish they were focused on more (I personally really care about things like this and gave tried to make a difference by donating/awareness, not much but the best I'm able to). For example, the 'this is what a feminist looks like' the shirts that Emma Watson, ed milliband etc wore were made by women in sweat shop conditions (although as this was some time ago, I can't remember where I read this).
The second reason why I struggle to identify as a feminist is that I don't particularly want to be grouped in with some of the more extreme feminists. I have read some awful articles about man hating and similar topics. Also, it only seems to be my friends that identify as feminists that have openly judged me on my lifestyle choices - eg wanting to stay at home and be a mother, enjoying taking care of my home and cooking while Dh goes out to work, dressing in a very feminine way etc.
I also know some lovely and understanding women who identify as feminists, such as my sister, but still struggle to call myself one because of negativity.