We present a brief personal history regarding an interest in problems that involve preserving filters on the integers that have no (infinite) pseudo-intersection while ensuring that many others have pseudo-intersections. The origin may have been with the beautiful results of Balcar, Pelant, and Simon concerning dense subtrees of P(N)/fin and the connections between the newly introduced cardinal invariant h and the other known invariants. We then discuss two recent joint papers with S. Shelah which utilize a novel modification of matrix forcing.