Chess coaching is often full of contradictions. While it is important for beginners to learn the virtues of solid, mistake free chess, this isn't the stuff that makes chess exciting. So after 35 minutes of 'put your pieces on safe squares, keep material even or in your favour', you wheel out the Morphy 'Opera Box' game to show them something interesting, and all they take away from the lesson is that you should sacrifice all your pieces to win.
Another good piece of advice is "develop your pieces before you attack". But if you are going to teach that lesson, then make sure you don't show the following game at any stage. It was played in the 1916 match between Janowski and Marshall (two obsessively attacking players for sure), but after 12 moves Black has only one developed piece, and he sacrifices that on move 13. Then with no pieces off the back rank, he proceeds to launch the mating attack. Not a great advertisement for the aforementioned advice.
Nonetheless it does serve as an example that chess is not just about one thing or another. In this case the other factors in play were White's lack of King safety (12.Qg4 was the culprit here) and Black's use of the open f and c files.
Janowski,Dawid Markelowicz - Marshall,Frank James [D00]
New York m3 New York (7), 1916
1.d4 d5 2.Bf4 c5 3.e3 Nc6 4.c3 e6 5.Nd2 Bd6 6.Bg3 f5 7.Ngf3 Nf6 8.Ne5 0-0 9.f4 Bxe5 10.fxe5 Ne4 11.Nxe4 fxe4 12.Qg4 cxd4 13.exd4 Nxd4 14.cxd4 (D) 14. ... Qa5+ 15.Kd1 Bd7 16.Qe2 Ba4+ 17.Kc1 Rac8+ 18.Kb1 Rxf1+ 19.Rxf1 Bb5 20.Qd1 Bd3+ 21.Qxd3 exd3 22.a4 Rc2 23.Bf4 Qb4 24.Bc1 Rxg2 25.Ra3 d2 0-1