I think a lot of men grew up with the idea that women are 'complicated'. Or they rationalised the idea that women are mysterious or hard to figure out because they don't get any obvious interest from them.

But in reality, women virtually always make it clear if they like a man. The trouble comes in the fact most men are undesirable to most women, so most men don't receive obvious signals of interest.

Many women are also looking to monkey branch to a better male, so one month a woman could be really into you and express her undying love to you. The next month she has forgotten you even exist. This is where men like to rationalise that women give 'mixed signals'. No, it's because she stopped liking you after she found a better man or simply believed that she could do better than you.

At the end of the day, if a woman likes you, you will know. If you have to look hard for signs that she likes you, then she almost certainly doesn't like you.