Ah to be in high school with the opportunity to learn a life lesson. In Poker (as in life) doing the right thing will not always result in victory, but that's not the point of doing the right thing. The point is knowing you did the right thing with the information you had at the time. Poker is not a single hand, or a single session or even a single year. Like life it is a stream of games and days. In the long run getting it in with KK will win you more money than it will cost you.
Let's assume your high school game has a large number of inexperienced players. What
hands do you suppose they would be willing to get All In preflop? AA, KK, QQ for sure. We just saw it. What else? JJ? AK? Let's look at the combinations There are 6 combinations of pocket pairs and 16 combinations of AK. Since you have KK thee is only one combination, the other pair of kings. 6+1+6+6+16=35 combinations the odds of one of you opponents having AA are 6/35 or 12/35.
Tripling your money when the odds of you having the best hand to start are over 60% is a good damn bet.
After all of the cards are out against 2 players with the a JJ+, AK range my odds calculator gives odds of winning as 42%. If you were heads up against that range you'd be a 62% favorite. AA doesn't always beat KK. nor does KK always beat QQ. in both cases the favorite is ~80% to win. The under dog has 5 chances to to get one of the two cards that will give him trips. At the same time the favorite has the same chance to get trips and occasionally you both will.
Suppose there were two players each with 20 BB. One player had AA and the other Ts9s. The Aces beat 3BB and 9Ts called. With 7 BBs in the pot, the flop came Qs, 9s, Td which hand would you rather have? Although behind now, the 9Ts is a 58% to win.
Finally, what is the alternative? Waiting to get AA before you are willing to bet? That is a whole lot of folding and who is going to call your bet after you fold 100 times?