I took a course in surviving captivity. They said that the people who have done best in prolonged captivity were realists. The pessimists pretty much rolled over and died immediately. The optimists held out as long as they could, but eventually cratered. The guys who stuck it out for years and came out relatively healthy, like John McCain, were realistic and accepting of their situation, however bad it got. The North Vietnamese even gave McCain a chance to be released, but he refused it because there were guys who'd been there longer who weren't going to be released with him. He survived because he didn't focus on either his hope or his fear, but on the other guys in captivity with him.

If you go through your life thinking of it as a search for a true heart who won't let you down, you won't forgive the people who let you down. You'll just discard them and keep searching. You'll be focused on judging the people around you, filling yourself up with fear and doggedly pursuing your hope, rather than focusing on taking care of the people around you. It's a self-defeating mindset. I can't prove that you can never find someone who won't let you down. But my experience and observation of people over 44 years tells me that you'll do a lot of damage to yourself and others during your years of searching and the years of bitterness and loneliness you'll almost certainly go through, after your heart goes numb and decides to give up the search.