First ET Interview: Joseph Gordon-Levitt

Joseph Gordon-Levitt is one of the hardest-working men in Hollywood today. Following his star turns in Looper, The Dark Knight Rises, Premium Rush and Inception, he also had a key role in Lincoln, just completed a turn in the director's chair for Don Jon's Addiction, and was just cast in the growing company of Sin City: A Dame to Kill For.

Video: What If 'Looper' Stars Could Time Travel?

Now, we're flashing back to the fall of 1995, when "Joey" was a very precocious young man working on a brand-new sitcom called Third Rock From the Sun.

Video: JGL Predicts His First Golden Globe

Watch the video as the fresh-faced, 14-year-old star talks about his "hormonal" alien character, Tommy Solomon, and the "eccentricity" of the show's writing.