- Learned to play piano at the age of 9.
- Was part of Edwin O. Smith High School's first graduating class.
- Landed his spot in the Monkees thanks to a recommendation from friend and fellow musician Stephen Stills.
- In 1972, he spent three months in jail for hashish possession.
- Portrayed Topanga Lawrence's father in episodes of the TV series Boy Meets World.
- Battled a rare form of cancer known as adenoid cystic carcinoma in 2009.
- Anne Elizabeth Thorkelson — Sister
- Reine Stewart — Ex-wife
- Barbara Iannoli — Ex-wife
- Erica Marie — Daughter
- Tammy Sustek — Ex-significant Other
- Jody Babb — Ex-wife
- Nick Thorkelson — Brother
- Hallie Elizabeth — Daughter
- Virginia Hope — Mother
- Halsten John Thorkelson — Father
- Christopher Thorkelson — Brother
- Ivan Joseph — Son
- Attended Carleton College, Northfield, Minnesota, United States