I think about space a lot, Space is the boundless three-dimensional extent in which objects and events 
Yeah I'm pretty fascinated by space too. There's so much that we don't know. I don't think I will ever get to go in my life time. 
I have heard  Physical space is often conceived in three linear dimensions, 
I have heard the same for the most part. Aren't things like black holes an exception or do we just not know enough?
We dont know wnough. some say The concept of space is considered to be of fundamental importance