On the eve of the Pill’s 50th anniversary, Melinda Beck of the Wall Street Journal looks at how far contraception has come and asks why, still, nearly half of all pregnancies in the U.S. are unplanned.

Beck points out that contraception still presents a financial barrier for many people, and that culture and religion complicate things. But, more importantly, she points to a behavioral tendency articulated by the National Campaign to End Teen and Unplanned Pregnancy in a 2009 report:

…many young people are in “the fog zone” in which their beliefs about pregnancy don’t match their behaviors… In a survey conducted by the Guttmacher Institute of 1,800 single men and women aged 18 to 29, more than 80 percent of both sexes said it was important to them to avoid pregnancy right now, yet 43% of those who are sexually active said they used no contraception or used it inconsistently.

People are not perfect. We’re not even (in my opinion) rational actors. That’s why we need A LOT OF HELP—education, improvement, support. Some of this has to come from ourselves and some of it has to come from others.

When it comes to education, we are still failing our youth. There is no doubt that sex education works. And yet many states continue to fight it. Recently, in Nashville, a peer education program was shut down because a condom made an appearance in class (Tennessee law “bars ‘contraceptive methods’ from being brought into the classroom or distributed by even guest speakers”). According to the Guttmacher Institute:

Most states, including some that do not mandate the instruction itself, also place requirements on how abstinence or contraception should be handled when included in a school district’s curriculum. This guidance is heavily weighted toward stressing abstinence; in contrast, while many states allow or require that contraception be covered, none requires that it be stressed.

People in many parts of the country, in all sorts of communities, are hostile to sex education. Guttmacher’s policy brief goes on to say that “several states require that education on sex and STI/HIV be ‘medically accurate’ and/or appropriate for the age of the students.” Several?? How about all? Sick as it seems, opponents of comprehensive sex ed have an interest in being able to be medically inaccurate—then they can cite outdated or fabricated statistics showing that condoms are only 70 percent effective or that birth control pills cause abortions.

So why, in a world of countless birth control pills, the ring, the patch, implants, and condoms for women and men, do people still get pregnant unintentionally? Because there are a lot of people rooting against them.