This is very possibly true.
Because really? I'm not sure I am an adult. It's highly likely I'm only pretending, which seems to be the underlying implication of the word "adulting." You're not really an adult; you're just faking it till you make it (or don't make it, as the case may be). You changed a lightbulb. You made dinner instead of eating chocolate. You got up, walked the dog, and went to work instead of calling in sick.
I'm not sure I'm fooling anyone with the whole adulting thing. Without even counting my large failures at previous life decisions, there are several other signs that I might not be a "real adult." For example, I've started wearing an Eeyore onesie around the house on more of my days off than I care to admit. I bought a Doctor Who shower curtain. I have coloring books. I still consider my birthday to be a holiday. I take way too many selfies. I think pigtails are an acceptable hair style. And I'm practically a teenager when it currently comes to being in love.
On the other hand, I've been paying all my own bills for a year and a half. I signed up for health insurance (finally). I worked events last Friday and Saturday, even though I had a cold, because, well, I had to. We had six events Friday and seven on Saturday. If I stayed home with Kleenex shoved up my nose watching Netflix, there would have been no one else to work. (By the way: sincere apologies to anyone who got my germs along with their photos. I tried to stay sanitized.)
To be honest, I feel more like an adult than I have in years, Eeyore onesie and all. I'm adulting all over the place. I'm adulting so much that I don't have time to do much else. Which is fine. It keeps me busy. It keeps me out of trouble. It keeps the bills paid.
And the weird thing is that still I'm enjoying my life more than ever before. Being an adult shouldn't be so great, based on the bad rap it got when I was younger. There are responsibilities and bills and broken appliances and divorce and too-little-sleep and a distinct lack of naps. I drink less. I'm fully accountable to another person for probably the first time ever, and I have no one to blame if I fail except myself. And I'm stressed and tired and usually just want to stay home and introvert with my boyfriend.
But. I wouldn't change much of anything.
And maybe pretending to be an adult is the best way to do it. It keeps you from being too serious, or from taking yourself too seriously. It lets you wear pigtails and Eeyore onesies while taking selfies and coloring in coloring books.
And if that means I'm not a "real adult"? Then fine. I'm not. But I'm getting pretty damned good at pretending.