The primary meaning of solitude is time alone. For some people a time of solitude can be lonely. For others it is a time for peaceful reflection, a moment of refreshment in a hectic life.
How people respond to solitude depends partly on whether a person prefers being extroverted or introverted. Early in the twentieth century, the Swiss psychiatrist, Carl Jung defined introverts as people who desire to think about ideas before expressing them. Introverts need periods of quiet solitude to reflect on life. Extroverts like to jump into life with full force, to experience all the flavors of life first hand. An extrovert will be satisfied with just a little solitude. Extroverts are refreshed by people and activities. Introverts are drained by people and events.
When you understand the difference between introverts and extroverts as preferring introspection or involvement then it becomes clear that introverts would want much more time alone than extroverts. For introverts solitude is a time to be immersed in ideas, thoughts, images. For them solitude is an interesting time, maybe even exciting. Extroverts who like to be involved with things and people can become lonely with just a little solitude. It is a matter of preference, but the preference seems to be rooted so deep in the personality that people seldom change preferences.
Because introverts need periods of quiet and solitude to become refreshed we often think of introverts as being shy. Actually both extroverts and introverts can be shy. Shyness has more to do with being uncertain about how new people and new situations will turn out than with introspection and involvement. Shyness comes from not being skilled at reading other people and from basic temperament.
Introverts sometimes begin to think that there is something wrong because they desire time alone, because they enjoy solitude. There are about three (3) extroverts for every introvert. Extroverts, by their large number set the standard for involvement, but even extroverts tire of activity and can enjoy moments of solitude. An extrovert might stop to ponder his or her life as a storm is brewing in the distance, giving just enough stimulation to make the time alone satisfying. An introvert might prefer a quiet room at home when the family is out.
Extroverts and introverts can complement each other in relationships with each helping the other to have a fuller life. If the differences are not understood and respected they can be disruptive. The extrovert can feel neglected and lonely when an introverted partner wants some time alone. The introverted person can feel harassed when the extroverted person keeps requesting more activity. Couples need to find ways to discuss their changing needs. A boring day at work can get an extrovert ready for activity at home. If the introverted partner had overly involved day he or she would be looking at home as a quiet haven. Couples need to discover ways to discuss these differences.