Hendrik Groen is the pseudonym of Peter de Smet, a celebrated Dutch writer born in 1954. He gained widespread acclaim for his works Pogingen iets van het leven te maken: Het geheime dagboek van Hendrik Groen, 83¼ jaar (The Secret Diary of Hendrik Groen, 83¼ Years Old), published in 2014, and its sequel Zolang er Leven is: Het nieuwe geheime dagboek van Hendrik Groen, 85 jaar (On the Bright Side: The New Secret Diary of Hendrik Groen), released in 2016. Both novels have been warmly received, with the first winning the prestigious Audience Award for the Dutch Book.

For years, the identity behind the pseudonym Hendrik Groen remained a mystery, leading to widespread speculation and intrigue in literary circles. In 2016, it was simultaneously revealed by both De Volkskrant and NRC Handelsblad that the real author was Peter de Smet.