i´ve listened to a buddhist monk on youtube once....
He said, if you´re alone, be happy about the fact you can do what you want when you want to do it. There is no-one you have to take in account and you can realize all your personal goals and dreams...
If you´re with friends/partner etc. be gratefull about the fact you can share moments, do stuff together, work togehter at common goals dreams etc.
it´s just....if you got one, don´t go wishing for the other, then you´ll be unhappy even tough you´re life is great.
from personal experience, i´m more of a social person, and i´m happy to be fortunate to have a few very nice people around me....still the best, most intense moments of my life i´ve lived on my own...