Alone

Alone. I spend a lot of time alone. I am basically a social person, but I crave that alone time. I think about it a lot. One of the things " I know for sure" is that we are ultimately alone. What is the tipping point for too much time alone, when alone turns into lonely?  I know I have reached that point many times, but I usually just find a project or pick up a book and do my best to turn it back into alone time. I was alone today and family came to town. I was a little irritated with my time alone being interrupted, but family wins, sometimes. I left and spent the family time, only to get a call that MORE family is in town. I decided not to go. Will these decisions of not wanting to see people ultimately end up in lonely when I am old and alone?