Jack Black was 36 in Tenacious D in The Pick of Destiny when he played the character 'JB'.
That was over 17 years ago in 2006.
Today he is 54, and has starred in 123 movies in total, 67 of those since Tenacious D in The Pick of Destiny was released.
In Tenacious D in The Pick of Destiny, I think Jack Black looks: