Danny Thomas ultimately recommended Mary Tyler Moore for the part of Laura, remembering auditioning her for his show the previous year.
Oh, yeah, I forgot.
In the first season, Rob calls his wife Laura but the odd time, calls her Laurie.
The most famous image of the opening credits is of Van Dyke falling over an ottoman as he enters his living room. However, a second version, showing him sidestepping the piece of furniture instead, was also used. The two openings were filmed back to back and were used randomly throughout the last four seasons of the series. The first season used a completely different opening credits sequence featuring still pictures.