To simplify the expression 1/b^2 - ab - 1/ab - a^2, we can first combine like terms:

1/b^2 - 1/ab = (a - b) / (ab^2)

Next, we can subtract ab - a^2:

(a - b) / (ab^2) - (ab - a^2)

To simplify further, we need a common denominator for the two fractions:

(a - b) / (ab^2) - (ab - a^2) b / (ab^2) = (a - b - ab^2 + a^2b) / (ab^2)

Therefore, the simplified expression is (a - b - ab^2 + a^2*b) / (ab^2).