Thank you for all the replies so far. I agree with with what's been said.
In most other situations, I would never have had a second thought about
letting others live their lives and make their own decisions and mistakes.
My only issue is that this time it involves someone I know rather well and
care about. And I get the feeling that it is this confusion that is causing
them a great deal of the dissatisfaction in their life.
So now I'm not sure if I can/should just watch them be miserable or if I should
talk with them about it.

Oh yes, and to all those that didn't laugh, I bequeath...a boot to the head.