"Over the past 10 years, my mom will bring up things like trips we went on or big events and they are new stories to me," Muniz told PEOPLE

Frankie Muniz on His Intense Struggle with Memory Loss & What He Can't Remember from Malcolm in the Middle

On Monday’s Dancing with the Stars, Frankie Muniz got candid about his experience with memory loss — and how he’s learning to cope.

In a pre-taped package for the Most Memorable Year night, Muniz, 31, touched on his many health issues and how they may have led to problems with his longterm memory.

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Speaking to PEOPLE after his performance with pro Witney Carson, which earned him a 24 out of 30, Muniz revealed his memory loss wasn’t always something he was comfortable discussing.

“It’s something that I never really wanted to talk about, because I’m just me and this is my life,” he said. “But we were talking about Malcolm [in the Middle] and how it started, and I don’t really have memories of being on the show.”

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Muniz said all he recalls of starring on the hit Fox sitcom, which ran for seven seasons from 2000-6, comes from “seeing an episode.”

“Over the past 10 years, my mom will bring up things like trips we went on or big events and they are new stories to me,” he admitted. “I don’t know what the cause of it is. It’s not something I looked into, I just thought it was how my brain is — so I thought it was normal. I didn’t know I should remember going to the Emmys when I was younger.”

“I’m not a doctor person,” he added. “Every time I go to the doctors they just tell me I’m crazy.”

Muniz, who suffered a serious car crash in 2009 while competing as a professional race-car driver, has also endured several concussions — but he says his health battle doesn’t affect his desire to work in Hollywood “at all.”

The star has also been working with his girlfriend Paige to help with his memory loss, and each day, she writes down what they do together in a journal.

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“She’s amazing,” he gushed. “She literally writes because I get sad at the thought of losing the memories. So she writes in a journal that I can look at every day and it’s really cool, because it has amazing detail. She started doing that about a year ago and hopefully she’ll continue. She’s awesome. She’s very supportive. I hope we have a lot more memories [together].”

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In his pre-taped package, Muniz said he’s “not actually sure” how his memory loss started.

“I have had nine concussions and I’ve had a fair amount of mini-strokes,” he said. “I’m not saying those things correlate exactly to the reason why my memory’s not great.”

“I’ve never been to the doctor and been like, you know, ‘Why don’t I have a memory?’ ” he said. “To be honest, I’ve never really talked about it.”

Muniz previously told PEOPLE he suffered his first mini-stroke, or transient ischemic attack, during which blood supply to the brain is temporarily cut off, in 2012. Unlike a stroke, there are no lasting effects. Since then, he estimates he has had 15 mini-strokes, varying in frequency and length.

Of the journal kept by Paige, Muniz said in the pre-taped package that he loves “to be able to look back” — even though it can be bittersweet.

“It makes make a little sad that it doesn’t just pop back into my mind,” he said. “Like, I should have remembered going to Australia. That’s something that people remember.”

PEOPLE’s special issue, 25 Seasons of Dancing with the Stars, is on stands now.

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Muniz’s Malcolm in the Middle co-star Bryan Cranston also sat down for the package to express his love and support.

“I told him not to worry about what you remember and what you don’t remember,” said Cranston, 61. “They’re still your experiences. That will be my job. I will tell him, ‘Remember this? Remember that from Malcolm? What a life for you!’ ”

“My most memorable year is 2017, because I learned to live in the present,” said Muniz. “I’m happy with my acting career, I’m happy with the decision I made to drive race cars and to focus on music. Even if I don’t remember it all, I’m happy.”