After a career with McLaren that began when it took him under his wing when he was karting and ultimately led to six F1 seasons together and the 2008 world championship, Hamilton jumped ship for Mercedes at the start of 2013.
"I recently read a very nice quote from Lewis in which he said that, unlike other drivers who had joined McLaren once they'd already raced in F1, his apprenticeship with the team in his youth meant that he was a seed that had grown within McLaren, which I thought was an extremely eloquent way of putting it," said Dennis.
"Lewis knows that he's part of the McLaren family and that, like that seed, he's grown deep roots within our organisation.
"Last year I didn't seriously seek to prevent his efforts to explore new pastures with the Mercedes AMG F1 team - perhaps it was a necessary part of his maturation – but I'll always remember his time with us very fondly, just as I'm very proud of having been McLaren's CEO and team principal when he became world champion with us in 2008."
Dennis added that the effort McLaren had put into nurturing Hamilton before he reached F1 should not be underestimated. The Briton came close to winning the title in his rookie season in 2007.
"The fact that he adapted so quickly was not only a mark of his hunger and ability, but also a tribute to the quality of the education and support that McLaren had spent so many years providing for him," said Dennis.
"While it wouldn't be unfair to call Lewis 'an overnight sensation' in F1 – and many understandably did – we at McLaren know that it took many years of unseen hard work to make him one."