We are flat out told that in 1976, both Mouse and Mary Ann are 26 and former lawyer Brian is probably closer to 30 (although I don't think that's confirmed). Flashforward to today (well, 2018) and suddenly the three of them are early 50s. 42 years have passed...

I guess what bothers me is that they could have just as easily set the story around 2004 and nothing would have really changed.