Mark Hoppus didn't mean to publicly announce his cancer battle.
The Blink-182 rocker confirmed he was facing stage 4 diffuse large B-cell lymphoma in June this year when he posted a picture of himself strapped into a chemotherapy chair on his Instagram Story.
And Mark - who received his diagnosis in April - has now said he actually meant to share the news with his close circle of friends and not with his 1.2 million Instagram followers, but "brain fog" from his treatments caused him to slip up.
He recalled to GQ magazine: "Throughout the day as I'm getting chemotherapy and more bags of chemicals are being dropped into my body, other people are reaching out and they're like, 'Dude, what's going on?'
"Chemo is like being on the worst international, overnight flight where you can't sleep or get comfortable. I felt so s*****. And the brain fog is so bad.
"Maybe part of me subconsciously posted it to my main, but I definitely didn't do it on purpose. But I don't know. It kind of felt like a Band-Aid had been ripped off and I was able to be honest with people."
At the time, Mark shared a statement on his social media account in which he admitted he was "scared" to face the disease.
He wrote: "For the past three months I've been undergoing chemotherapy for cancer. I have cancer. It sucks and I'm scared, and at the same time I'm blessed with incredible doctors and family and friends to get me through this."
In September, Mark then announced he was in remission.
He said at the time: "Just saw my oncologist and I'm cancer free! Thank you, God and universe and friends and family, and everyone who sent support and kindness and love.
"Still have to get scanned every six months and it'll take me until the end of the year to get back to normal but today is an amazing day and I feel so blessed."