Do you really think that kind of thing ("man behavior"

) is what defines you as a man?
If we are not allowed, by society, to act that way, it's taking away part of us, yes. I'm not saying all men have to act like brutes but neither should we be kept from it. Sometimes we really do just want pizza, beer and a ball game.
Sure. People establish their gender identity- if they want one at all- in various ways. I identify strongly as "male", but in my own unique way, and with my own idea as to what that now means
for me. My concept of "male" or "female" is not defined by any traditional concept of social role, personality, etc, nor is it universal. I know what to
me fulfills my identity as "male", but it does not apply to all men by any means, nor would I try to extend it. As
Mr. Laser Beam said, some people embrace traditional gender roles, and there is
nothing wrong with that. If a man wants to be "a man" in the traditional sense, and finds meaning in that, or a woman wants to be a "traditional" wife and mother, well fine (so long as they aren't imposing that role or ideal on others or suggesting everyone should share their worldview). Ideally, it should be about choice, not about limiting people's options by declaring whole swaths of human behaviour off limits.
I mean, my dream in life is to be a house-husband, to raise children and provide loving emotional support for a breadwinner, career-driven wife who supports us and is fulfilled in her career. But some people insist that to be in the home dependent on your spouse is something no-one could wish for! Nonsense. Neither the traditionally male nor the traditionally female social role is by default
bad, nor by default good. It's all about who you are. There are always sacrifices to be made, always fulfillment to be found. The only difference is that in times past you had to make specific sacrifices due to gender and so many people were sadly unfulfilled and frustrated. You just have to possess the freedom to match your personal strengths and character to a role (or switch betwen them if you can, and want to). My generation is priviliged to, on the whole, possess that freedom, which our ancestors could not afford. And it
is privilige, not entitlement. Our society has managed to prosper enough that we can choose, not bury our individuality under ideals of duty and neccessity. Preserving such a society is also an on-going effort, which is why I say we should never assume that we have any "right" or entitlement to these personal freedoms- we instead have need to keep society stable and prosperous so we don't fall back into the necessities-of-survival model.
Suggesting that "manliness" or the equivalent "feminine" role are by default
bad not only limits choice but is dangerous to humanity's prosperity- we need these aspects of our race to thrive. It was the "manliness" subculture that built- and builds- the bridges and houses and churches and roads and dams all around us, which catches the fish and mines the raw materials and defends our homes. And it was the stereotypically feminine, demonstrative, nurturing role that allowed our children to thrive and tied our families together. And if someone
wants to align their gender identity with their personal preferences and embrace tradition, that's all well and good- just as it should be well and good to totally sunder gender identity from traditional social roles and assumptions.

Just because we no longer have to be traditional, doesn't mean we can't
choose to be.