Beliefs depend on the available information. This idea is formalized in probability theory by 3 Conditions; Probabilities, Expectations and Distributions are treated on 3 levels... 
 
These levels lead to a non-random result if this is completely
specified; otherwise, if this is left random, the result is also random.
 
Example. A fair coin is tossed 10 times; the random variable X is the number of heads in these 10 tosses, and Y — the number of heads in the first 3 tosses. 
 
In spite of the fact that Y emerges before X
 
It may happen that someone knows X. But, not Y.
 
He's a probability, She's a probability, You're a probability, They're a probability, I'm a probability and MOST IMPORTANT; We're a probability of the Universe (GOD/ALLAH/JESUS/MUHAMMAD/US).