I've always hated the saying "boy will be boys."
Even when I was little, it made me uncomfortable, though back then I didn't have the vocabulary to articulate why exactly. It made my skin itch whenever I heard the phrase being spoken, and now years later, I have some clarity to understanding why.
The phrase is a gateway to sexism. It let's young males off the hook for specific unsavory actions that they might commit during childhood into adolescence. A young girl could commit an identical action, but she most likely won't be met with the same response. Instead, that young girl will probably be told "that's not ladylike" or to "apologize for her actions."
This notion of double standards only intensifies as the individuals grow. When little children are given toys to play with, young girls often are given dolls, arts and crafts, or other domestic items. Little boys are commonly given Legos, puzzles or other problem-solving activity designed to stimulate the brain. Little girls are privy to these experience until much later in their lives because they are automatically assumed not to be interested in complicated "boy things."
On the same note, it's almost unheard of to purchase a little boy a Barbie unless he specifically asks for it, and even then the concept of a little boy playing with Barbies isn't widely accepted. I remember I use to put my little brother's hair in tiny pigtails when he was a toddler. He didn't mind, he actually liked it if I recall correctly. But even that small action was unwelcome by some of my family members.
When adolescents begin dating a whole new set of double standards come into play. If a girl is casually talking to multiple men, her actions are regarded as slutty. While a man could physically be hooking up with multiple women, and it's seen as typical male behavior.
When it comes to emotions, it's more widely accepted as normal for women to be expressing their feelings constantly, but it's seen as weak for men to do the same. Men are supposed to be the strong gender, while women's emotions make them fragile. Neither of these mindsets is healthy or benefits anyone.
The last double standard I'm going to address is physical appearance. As I said, it's commonly perceived for men to appear tough which stems greatly from the idea of a built physical appearance. A man is supposed to be big and muscular, while it's more favorable to a woman smaller. When a woman is physically stronger than a man she is often deemed as intimidating, and if a man is on the smaller size, he's perceived as weak.
Toxic masculinity and set ideas of femininity are equally destructive to both genders. There is no "right" version of how to embody a functioning woman/man. I personally have no interest in being domestic. I want to chase my own dreams and work towards my own goals. I embrace anybody, from any gender, who wishes to do the same. At the same time, I applaud all the men and women who do want to settle down and create a life for themselves with a family. I find that dream beautiful and wish them all the best.
There are so many wonderful ways for every gender to create a life for themselves and I think it lessens the possibility to have these great experiences if we keep letting gender-based ideas determine how we live. This change isn't going to happen overnight, but this expectation starts at the very beginning. So make your next gift to a little girl be something that helps to challenge her brain, and your next gift to a little boy something that lets him express his creativity and feelings.