Everything to lose

Be financially stable.
Be successful in a career.
Be part of a happy, functional relationship.
Have a family.

These, along with others, are items on my mental checklist for success. Success, of course, leading to contentment and hopefully, happiness.
The intriguing part is that singularly, these accomplishments seem to mean little. Being in a good relationship seems to mean less when your work life is a nightmare. Similarly, being a successful workaholic means nothing if you're alone at the end of the day.
I always felt that when I was able to simultaneously "check off" the items on this list, that I'd feel complete. I look at people who are married, have kids, or who are successful and financially independent, and think that they should feel like they have it made.
There's another side to that coin, which I had never considered.
Accomplishing your dreams, or achieving your heart's desire opens you up to the possibility of loss. When you are with someone and everything seems perfect, you can't help but consider the possibility that it is fleeting; that within moments, that perfection could be gone.
Even worse, you can spend your life dreaming of a future -- of the perfect mate, the perfect house, the perfect job. Then, marriage isn't what it seemed, the house is less than ideal, and the job, well, the job isn't what you wanted.

“There are two tragedies in life. One is to lose your heart's desire. The other is to gain it.”
- George Bernard Shaw