I know this, like all QnA threads, is a total shit post, but just in case here's an actual list of everything you need to know to understand men (and a bit on women):
Men are able to have entire conversations solely through head nods or simple guttural sounds, and men can restart an old conversation right where they left off even years after they last spoke to a friend. This is famously lampooned in many episodes of King of the Hill.
Men tend to be very visual oriented, more so than women, hence their interest in visual porn, video games, and other visual art/media, over written language. They also tend toward tactile learning, that is, they learn by doing something rather than listening or reading about the task. This is why men typically do poorly in standardized schooling, especially younger boys, and is why boys play and fight each other before puberty.
On a related note, men, especially when they are younger, tend to make friends through fighting and don't really hold grudges (at least the way women do) but will develop a sort of quiet respect for a former foe, even if they beat them in the fight. Women by contrast will pretend their enemies are their friends, and call it a clique, while scheming their entire lives to one-up the other members of the clique.
Men do not care about social status of women. At all. A billionaire will happily marry a waitress, a prince will marry a teacher, a president will screw a pornstar, and so on. Men also do not really care about social status of other men, beyond some natural competitiveness when around attractive women. But ultimately "bros before hos" will tend to win out even then. A rich man will remain friends with his high school dropout friend who works as a janitor, and they'll play basketball together every weekend. Social status between males only really matters in countries with very strong class divisions, such as many Latin American societies, and even then it's often relaxed.
Women are the exact opposite, as social status is their primary currency in life. They will obsess over the status of everyone in their lives, especially their boyfriends, purely to one-up their "girlfriends". They will also tend to subconsciously believe that men think like they do, and will try to develop themselves to appear more attractive to men by doing the same things they look for in men, for some reason thinking that men care if the woman has a college degree or makes a lot of money rather than just her physical appearance and level of annoyance being around. This is not the case, see the previous point. Much feminist angst has been wrought by this fundamental misunderstanding of men's interests in women.
Men are naturally stoic. Women tend to misread this as "bottling up" their emotions, but the reality is that men just don't feel negative emotions the same way women do, especially after puberty begins. Fear is generally a much weaker feeling, and men's natural practicality renders sadness less effective as men don't dwell so much on grief and focus that energy instead on providing for others. Anger can still be very strong, however. Most men can barely tear up even from severe pain, but rage will make them cry outright (this is likely a leftover survival trait, as tears clean and protect the eyes during a fight). If you see a grown man crying, either he's really, really pissed off or his child just died; either way, he's about to kill someone.
Men have a strong natural preference towards virtues, especially loyalty and will react very strongly to betrayal. This is the opposite in women, hence why women are more likely to forgive a man for cheating and are also more likely to cheat on their husband than the other way around.
Men mentally stop developing at roughly age 25, due to final changes in brain chemistry that happen around the mid-20's. They will also tend to go through a series of period of depression/introspection/existential dread, the first around age 19 usually resulting in panic attacks or suicide, the second and strongest sometime in their mid-30's; this latter period is usually derisively called a "mid-life crisis" by women and media orgs. It should more accurately be called "self-improvement", as most men react by losing weight, gaining muscle, developing a business, investing their money, or otherwise getting their lives in order. Or they kill themselves. This period (age 35 to 50) is typically when men are at their most productive financially; virtually all millionaires/billionaires make their first million/billion during this period, while most artistically creative people have their greatest productivity in late-20's. The final period is around age 65-75, depending on health. If an older man's health is poor, he'll suicide as part of a natural urge to stop burdening his family.
Women mentally develop faster than men, but stop mentally developing at around age 14, which will be closer to a 16 year old male's mental development. Women will tend to feign bisexuality/homosexuality/or other degenerate behaviors (choking, extreme sluttiness, etc) in their late-teens to mid-20's in an attempt to appear more interesting to men. They will physically age out of the dating market at 33 to 37, around the same time men are going through their self-improvement cycle, and (especially if not married) these women will spend the next 40+ years screaming about young women dating older men out of a sense of petty rivalry with more attractive younger women. Women are far less prone to suicide than men at any age level, but those who do will tend to feign suicide in their early teens, late teens, late twenties, late thirties, and so on every decade or so, almost always as an attempt to get attention and not a serious suicide attempt.
If you can incorporate even 10% of that understanding of men into a book, you'll be able to write male characters better than the vast majority of female authors. You don't really need to know more about men than that.
View attachment 5301260
If you can answer the riddle of stick, you'll be ready to write men.
I unironically have about ten good sized sticks in my room as I type this. And an old bat against the wall for good measure. There's a big tree limb I cut to length sitting in my truck bed and it's been there for at least five years now. No real reason why I didn't burn it with the rest of the tree, but it was a really good stick. Feels good to swing at stuff.