Answer:
I'm where yesterday follows today and tomorrow is in the middle. What am I?
I am what bring things together. Without me everything you see would be a total mass or debris everywhere.
I open to close but I close to open. I'm surrounded by water but I'm never soaking. What am I?
What is black when you buy it red when you use it and gray when you throw it away?
By myself, I'm practically nothing. Worthless as a leader, but when I follow a group, their strength increases tenfold. What am I?
The answer I give is yes, but what I mean is no. What was the question?