Jay Leno thinks his marriage is "defined" by how he cares for his wife following her dementia diagnosis and not just about how intimate they have been over the years.

The 74-year-old comedian reflected on the ups and downs of his relationship with Mavis, whom he’s been married to since 1980, during an appearance on In Depth with Graham Bensinger, which aired on Wednesday. Jay confessed that before his wife was diagnosed with dementia, he never felt like he was “challenged” in his life.