Any way to see which rows in a data set have the most common values?

SOLVED by u/Bradland, thank you!

Hello everyone!

I have a simple dataset that is a row per person (300ish in total) that has their name in column A, and then 5 things that they have chosen from a predefined list in columns B to F.

What I'd like to do (but can't quite figure out) is how to determine the number of things each person has in common with everyone else.

I've tried something with sum(index(countif(B$2:F$2, B3:F3))) which I can drag down to compare the 1st person to every other person. However, that leaves me needing to write a formula per person, which I would prefer to avoid.

Any ideas?

Edit: my title may be misleading. I want to know which rows have the most in common with other rows. Not whether the rows contain the most common values. For example, I'd like to know if person 1 has the same 5 things as someone else, etc.