I have recently been playing some pre-season warm-up games. I came across a nice little tactical situation in one of my games yesterday whereby I can sacrifice both my rooks and achieve a checkmate with my Queen ... This is a common tactical motif when studying the concept of 'breaking down the enemy walls and stripping the King if its defenses'. I seem to remember attempting a similar exercise on C.T.Art3, which incidentally is an excellent bit of software if you want to practice tactics.
For those not yet acquainted, tactical breakthroughs are all about giving up material in the short-term (only temporarily) and making a profit after the final exchange (or even better, winning the game with checkmate)!
"Chess is a form of intellectual productiveness; therein lies its peculiar charm, and intellectual productiveness is one of the greatest joys of human existence".
Dr Siegbert Tarrasch (1862-1934), The Game of Chess, 1936, translated by G.E. SMITH and T.G. BONE.