[AznHisoka]

What's the difference? If he/she is wrong for you, who cares if he/she isn't right for someone else?

Very little consolation (if any) if he/she turns out to be the right person for someone else.

[kazinator]

What's the difference? Hmm, perhaps a car analogy. "Wrong car for you" might be a two-seater sporty thing, and you have five kids. "Wrong car for anyone" has brakes that suddenly stop working.

[a3n]

My ex wife was a Volvo station wagon whose brakes stopped working.

[LordKano]

You can have a grown-up, amicable breakup with the wrong person for you.

The wrong person for anyone will destroy your life.

[Vraxx]

In fact, the first thought I had on the matter is it's actually a little depressing if he/she turned out to be the right person for someone else and yet the two mistaken people suffered together for some number of years that could have been bliss with someone else.