I once read a book called adrift [1], a true story about a man adrift at sea, alone, for 76 days. The main takeaway that I recall was the profound loneliness and the desire for human contact that he experienced. I sometimes think of this I'm with friends and family, to try to really appreciate the moments that I'm with them. Luckily, I don't feel the need to impose 10 days of solitude on myself to obtain this realization (nor the other realizations the gained by the author of the post).

[1] http://en.wikipedia.org/wiki/Adrift:_76_Days_Lost_At_Sea and http://en.wikipedia.org/wiki/Steven_Callahan