Here's another thought - until very recently, motherhood was something that just happened to most women. (My father likes to point to a photo from my parents' 40th anniversary party, where they were surrounded by all their grandchildren, and say, "See, here's a dynasty that basically started because I was horny!") Couples got married and kids followed - but these days, because of the miracle of birth control, motherhood is a choice, and consequently we feel all this pressure to make it an all-encompassing, thoroughly blissful, utterly rewarding choice. "I wanted this - I should feel more blessed!" And then when we have those moments of frustration with our kids, exhaustion, boredom, etc, we feel guilty for not enjoying it, for not being consumed with gratitude.
I'm not advocating going back to the 50s/60s model of parenting. That wealth of information that confounds us also taught me that there are better remedies for teething pain than rubbing bourbon on a baby's gums. And thanks to birth control, couples don't have to get married at 19 to have sex, and I was able to choose when I had my kids. But like any huge social change, this evolution of motherhood is bound to be a bit rocky for those of us in the trenches. So we need to give ourselves permission to keep what worked from the 50s motherhood model - I read one article by a well-respected pediatrician who advocated less helicopter parenting and more 'benign neglect' - let your kids be bored, let them figure out how to make their own snacks, let them fail a test if they don't study, let them be hungry if they don't like what we're serving for dinner. We survived! (We also survived lead-based paint, station wagons without seatbelts, and sunbathing without sunscreen - kids are pretty darned resilient.) Our mothers had a host of other problems with which to contend, but for the most part they didn't drive themselves nuts worrying about whether they were good mothers, or feeling guilty because they occasionally didn't like being mothers, they just did it, or sent us out to play and figured we'd come home when we were hungry or bleeding.
Maybe we can embrace what works about modern parenting (helpful information, knowing that we are an important influence on our kids) but retain some of the common sense our parents practiced, and remember that we're all just doing the best we can at any moment, this is an incredibly difficult job, and no one is perfect. And a sense of humor always helps - when my boys are driving me crazy with their fighting, I try to remember when they also crack each other up with hideously inappropriate humor. (My 14-year-old taught the 11-year-old a trick from doing musicals, where the boys would add ". . . in my pants" to every song title. This resulted in such boy-friendly jokes as the song list from Music Man, including "76 trombones in my pants", etc. . . . . ) Ah, the joys of being a mom!