Matthew Mcconaughey has written a memoir.

The 50-year-old actor - who is one of the best-paid stars in Hollywood - has revealed that 'Greenlights' will be comprised of his personal journal entries and musings, describing it as a ''playbook based on adventures''.

He told ABC News: ''This is not a traditional memoir, or an advice book, but rather a playbook based on adventures in my life.

''Adventures that have been significant, enlightening, and funny, sometimes because they were meant to be but mostly because they didn't try to be.''

The Oscar-winning star has also discussed the memoir on his Twitter account.

In a video clip on the micro-blogging platform, McConaughey said: ''Ever since I learned to write, I've been keeping a journal. Writing down anything that turned me on, turned me off, made me laugh, made me cry, and made me question what kept me up at night.

''Two years ago I worked up the courage to take all those journals off into solitary confinement just to see what I had and I returned with a book.''

The movie star also revealed he named the memoir 'Greenlights' because it's about how ''we all can catch more of them in this life we're living''.

McConaughey - who has Levi, 12, Vida, 10, and Livingston, seven, with his wife Camila Alves - added: ''We don't like the red and yellow lights because they take up our time. When we realise that they all eventually turn green, that's when they reveal their rhyme.

''That's when life's a poem and we start getting what we want and what we need at the same time.''

'Greenlights' is set to be released in October, but is already available for pre-order.