I think in some ways this adjustment into parenthood is almost a bit easier on moms, in that it is more sudden. You HAVE to adjust, because you have no choice. Especially for mothers who stay home, even if just for the first few months, and who breastfeed, you are suddenly thrust into this whole new world where this person is literaly attached to you nearly 24/7, and in order to cope and survive you have to accept that nearly every aspect of your life is now entirely different, and that is just that. I look back on what my life was like before and then after having Donovan, and it's like entering a new dimension.
Most dads go back to work sooner, just a few days or a week or 2 after baby's birth, and so while their lives change radically as well, their direct, day-to-day experiences aren't nearly as different. They still get up and go to work, do the same stuff at work, and there's a few hours in the evening whre they come home to mom and baby. They might help at night when baby wakes up, depending on their routine and whether mom's breastfeeding. So I think the transition takes longer to take hold an to get used to, because it's not so... obvious. I remember joking with a friend a while back about how livid we each were upon hearing our husbands comment that those first weeks/months weren't "all that bad" to others, while we ourselves felt like we'd been sucker-punched in the gut with no chance to catch our breaths. I don't mean to say anything negative about dads in any way, this is not saying that dads aren't pulling their weight or helping out-- Zach has been incredible since D's birth, taking on more than his share of the housework and supporting me as much as he can emotionally. I feel incredibly lucky to have such a loving, helpful, and understanding husband. I think the adjustment thing is just a result of the way the roles get divided up. I also wonder if often dads are more likely/willing to speak up about what they want/need, while moms might behave more like martyrs and just keep trudging along, nurturing others and letting their needs be the last to be tended to.
I'm kinda just spilling out thoughts here, would love to hear others think of all this.