The hashtag #WhenIWas started trending nationwide on Twitter Tuesday as women poured out their stories of sexual harassment and abuse from childhood and adolescence.

It started with a series of tweets from Everyday Sexism, a feminist project dedicated to cataloguing women's daily experiences with sexual harassment, discrimination, and assault.

#WhenIWas quickly went viral and had about 30,000 tweets by early Tuesday afternoon.

Some women tweeted horrifying stories of sexual harassment and assault from when they were children or young teenagers.

Too many stories involved teachers who were either indifferent to the harassment of girls or actively enabled it.

Women also tweeted about how they faced discrimination in math and science classes, or dress codes that shamed and objectified their bodies even before they were sexually mature.

Some women tweeted about more ordinary, yet still outrageous, incidents that might have been their first conscious introduction to sexism.

Taken together, much like 2014's #YesAllWomen, the tweets paint a picture of just how common, and how harmful, these experiences are for women.

One in four girls and one in six boys will be sexually abused before they turn 18, according to the National Sexual Violence Resource Center.

#WhenIWas is about those children, but it's also about more than that. It includes some of the more common, and more insidious, forms of sexism that many women feel they have no choice but to shrug off and try to forget about. And it shows how many women have had to deal with this for literally as long as they can remember.