His 1999 appearance on the Daily Show confirms it. Especially the part where the interview turns into a psychoanalysis session.
Here is JGL promoting 10 Things I Hate About You. As you will see, he is basically a bumbling, awkward, anxious old Jewish man.
But dear lord, I love this man. No matter what his physical or mental age might be.
He's got the humor down.
He's got the schtick with the shoes.
And when Stewart is weirded out when JGL begins to remove his shoes, Joey's all:
