Here is a Tough Thing: sometimes people who are, on paper, excellent and clear-headed and fun and cool mix with others, and the result is more horrendous than a 1970s Jello salad. Early-twenties people are out to find fun characters, after spending their teen years in social circles where there often wasn't a lot of choice (i.e., high school). Late-twenties people have often discovered that even perfectly good, charming people can completely fail to mesh emotionally, and can do some pretty disastrous things to one another.

It's a hard lesson to learn, but toxic behavior can creep into relationships in unexpected ways. The friend who calls you in the middle of the night repeatedly to sort out her life without doing the same for you, the partner who's chronically insecure and can't be reassured that you do, in fact, like them: at their hearts they may be good, worthwhile people, but they can still act incredibly immature. And it's important to know your limit in dealing with them.

As you get your first serious adult job, your first apartment, your new sets of friends, your set of serious romantic relationships, revelations about old, toxic patterns may begin to surface. It's often only with distance that we realize that dynamics are, or have been, deeply peculiar or at least worth questioning. This is particularly the case in deeply embedded toxic patterns that have been holding for years, as with long-term friendships, parents or siblings.

I call this The Creeping Sense Of "...Wait". The Creeping Sense can take years and a lot of therapy, or just jump out at you like an angry opossum, but it has the same abrupt affect: things you thought were normal or simply a bit odd suddenly start to attain more depth and context. Perhaps it suddenly becomes apparent that being called in the middle of the night for no reason, or dealing with passive-aggressive texts, or feeling depressed every time you come back from a visit, isn't normal. It's not pleasant. Nobody likes The Creeping Sense. But it's necessary to develop an understanding of healthy behavior.

Often stories about journeys to adulthood have one trajectory: from "taking everybody's bullsh*t" to "not taking anything from anybody." The reality, however, is that we're more able to deal with interpersonal nonsense at some times than at others. Sometimes we have more time and energy to sort out the problem, take on the issues, and do some emotional work. Other times we just want to throw the entire toxic package out the window and eat our breakfast in peace. This is not failure. This is life. And how we deal with boundary-crossing behavior, our own and that of others, is not one-dimensional.

Oh god, that one ex. The decade of 20 to 30 appears to be purpose-built for everybody to experience the difficulties of A Truly Horrendous Romantic Partner. (Somebody made this compulsory, like getting a run in your new tights. Don't ask me why.) Maybe they ghosted you, or cheated, or cried in your kitchen at 3 a.m. and then pretended they didn't know you the next weekend, or were just generally interpersonally messy. You know you had one.

The thing is that often, these people aren't toxic in and of themselves — the two of you just produced something rotten and offensive through inexperience, insecurity and young adult idiocy. Cycling through the jerks out there allows you to pick out truly toxic behavior from the nonsense. (And sometimes they really are just awful.)

The most common advice for toxic relationships is often to cut the person out and shut off all avenues of contact. But toxicity doesn't have to stay toxic. I've been blessed with some truly batsh*t parents, and after a very rocky period in my late twenties that was highly unpleasant, we're talking and getting there. One, I've had a lot of therapy, and two, they are proving willing to change. If everybody puts in work — true work, not just "I'll say it to keep you happy and then fail to do anything substantive, or start and then give up" — there's hope.

Writing about toxic relationships and parents has been enlightening. And the predominant thing I've learned is that there are points where enough is goddamn enough. Sociopath parents, narcissist partners, jerk siblings, friends who wouldn't know a personal boundary if it bit them: We're not designed to be constant shock-absorbers for other peoples' abuse, double standards or gaslighting. It can take a while to know exactly what your that's-it lines are, but here's another trick: as you get further into your twenties, your spider-sense for toxic signals will get more enhanced. You'll be able to spot symptoms when they surface the first time, and decide whether to simply tap out early. And the more toxicity you've experienced, the better you'll be. Like a detective of terribleness.

What is OK for you? What is not OK? Your emotional boundaries are a series of lines in the sand: what you're willing and capable of putting up with and what you view as acceptable. The basic definition of toxicity is behavior that crosses your boundaries, repeatedly, and without attempts to fix the problem. Everybody does something wrong occasionally, but stuff that goes across your no-go line, whether it's invasive, bullying, passive-aggressive or in any other sense, should always send up a flare. And while open boundaries and being all-accepting and all-nurturing is often pushed onto women, it's much healthier to have a sense of your own "do not past go" point.

I'm looking forward to my thirties, partially because I'm hoping I will finally stop getting pimples, but also because years of dealing with toxicity has made me into a Toxic Grand Master. Here's to a decade where I deal it the roundhouse kick it deserves.