June 18th marks 18 years to one of the very popular Newgrounds songs from the 2000s. The song has just become and adult. If you're wondering why it's so important, NG would not be the same without it. It was also featured in The Impossible Game, then that inspired GD.
It was released in June 2007, when I think of June that year, I would not remember any events from that time as I was very young, I was not even in school. I do know I would spend days at home everyday until August, as it was during summer.