A tough question; all good responses.
From having sought this and failed in romantic relationships, my sister said to me one time, "You shouldn't be feeling this nervous and anxious...You should be feeling PEACE!" So, yeah, I think when it's right, there is peace of mind, comfort, and assurance between two people.
As for people who just don't know how or can't love...that was my ex husband of 20 years. I tried desperately during all of that time to buy into the "love is a choice" theory. It just didn't work.
Patty