| Last updated
Six years ago, Daniel was involved in a traffic accident, which badly damaged his brain and left him with a 'six-hour memory'.
In the weeks and months that followed the crash, he underwent intensive physio and speech therapy to help him regain his old life. Something he is still searching for.
While he is able to care for himself, he is only able to recall things in a linear fashion for six hours, and if he doesn't make a note of places he's been and people he's met, they will disappear completely after a day.
The accident also affected his relationships, leading him to split up with his then-girlfriend and to grow apart from friends he no longer remembered or felt connected to.
Even with former partner Katharina - whom he met after the accident - every day was almost as if it was the first time they'd met, with Daniel unable to share any memories of their relationship.
Speaking in the documentary Living Without Memory, about the crash, which he has learnt from notes, Daniel says: "That's the day I didn't die. It wasn't exactly normal that I made it, and that's why I look at that day in a positive light."
He explained: "I was going to see my sister. I was on the motorway. There was a traffic jam and I was the last one to join it.
"I was sitting there and then a car came up behind me, it was a big seven-seater with a young family inside, and the driver didn't see the traffic jam at all."
He added: "He smashed into me at over 80mph. The entire motorway was closed. There were a lot of injuries, but they weren't too serious. I was airlifted to hospital. I suffered a severe traumatic brain injury - they call it a level three TBI."
The injuries were so severe that he is now unable to transfer short-term memories into long-term, meaning that between going to sleep and waking up, he will have forgotten everything that has happened that day.
In order to remember what he needs to do or what he has done, Daniel writes numerous lists and keeps an incredibly detailed diary of everything he's done so that he can look back on it the following day.
When he met Katharina, he told her about the crash and that they had to see each other in the next few days or he would have forgotten who she was.
"I'd need to get in touch by the third day at the latest," he said. "I'd need to hear her voice or we'd need to talk, and above all, see each other.
"Otherwise it would be like meeting her for the first time."
But despite his limitations, he has been able to move on with his life, dedicating much of his time to helping other people with a similar condition, creating a group for dozens of others like him.
He also visits schools, businesses and other organisations to talk about it.
And a few years ago, he and Katharina had a little boy, Levi, which brought with it another series of challenges.
While most parents are able to cherish the memories they have of their children, Daniel's can't experience his son growing up.
"I can't remember my son's birth, and that's really horrible," Daniel said.
He explained that having to deal with his condition on a daily basis is like 'learning to swim' and that it takes its toll on him mentally.
"Unfortunately, depression is common among brain injury sufferers," he admitted. "Not for everyone, but sadly, it's normal for me.
Speaking about making the documentary with Daniel and Katharina, who have now separated but remain very close, filmmaker Nadine Niemann said it taught her about the importance of memories.
She said: "The most important thing was how important memories are for our life, for our relationships... For every kind of relationship.
"And I learned a lot about the importance of our brain and that we (or scientists) still don't know much about how it works the way it does. I appreciate my memories much more now."
Chosen for YouChosen for You
Most Read StoriesMost Read