Does Loneliness make you stronger or fragile?

I recently read a wonderfully accurate quote... "life's circumstance accounts for about 10% of what happens to You...and 90% How you respond to it" For the most part, I lead an extremely social work life...yet, on a personal note, my life is introspective, quiet and cerebral. Do I feel lonely? At work, NEVER. Outside of work? I sure do. How do I react to it? I do things with friends and acquaintances if I feel as if a rut is coming. At the very worst, I can always do something by myself...like watch a movie or catch a ball game, heck...I'll even sign up for a cooking class or go to a museum. Never rely on others for your own happyness!!!