Months ago now, I wrote about the idea that men who identify as feminists or feminist allies have to watch out that they don't get caught up in too much 'armchair feminism'--that is, we have to keep in mind that we may too often slip into a detached sort of conceptualizing of feminism, in part because we don't as often or as easily find ourselves face-to-face with the harms that patriarchy and misogyny can cause.
But the more I read and think about the conceptual frameworks that help create our relationship to gender and to power, the more I think that men can gain some motivation for better understanding feminism by paying attention to the ways in which patriarchy harms boys and men. This is not to take away from how these things harm people of other genders, of course--and for many people, avoiding harm to others is a pretty powerful motivation. But for many of us, avoiding harms to ourselves is also a powerful motivator, and I think feminist men should better understand this.
Thing is, the harms that men experience as a result of rigid gender roles, rigid hierarchical societal structures, and the like, are sometimes more subtle than the harms that women often face, or harder for men to see. Some of this just has to do with the way that men are harmed by rigid gender roles, and some of it flows pretty directly from men being at the top of the dominance hierarchy--it's tough to see the water that we're swimming in.
In addition, because of the very way that masculinity is envisioned and enforced, often these harms go unclaimed by men themselves, for fear of being seen as unmanly. Rather than, for instance, feeling the immediate, visceral effects of being verbally accosted while doing something like trying to buy some gas, men have to face the stress of being thought of as, and being taught to think of themselves as, protectors and providers, even in contexts where such things are impossible (as one example). Which is not to say that women don't face subtle forms of harm, or that men don't face visceral, physical and obvious harm in part by virtue of conceptions of masculinity--but it may be that men need to more often look harder to find a harm that exists.
Part of the risk of armchair feminism for feminist men comes from not recognizing these harms--once recognized, we might better feel the passion of our ideals.