Can any1 think of a scenario where "focusing on main thing" can be ill

Question:

Can any1 think of a scenario where "focusing on main thing" can be illustrated.?

Since 'focusing on main thing' is one of many leadership traits. I am struggling to build a scenario for role play for a leadership class that I will be presenting. The scenario can be from anecdotes from real life, or fables, work place etc. Just that it should be short and easy for a group of people. So that at end they feel "Aah I get it"

Best Answer - Chosen by Asker:

Canadian Corporal Rob Furlong of the third battalion Princess Patricia's Canadian Light Infantry (3 PPCLI), during the invasion of Afghanistan, using a .50 BMG (12.7mm) McMillan TAC-50 bolt-action rifle dropped a raghead at 2430 meters (7972 feet). The bullet had a flight time of ~4.5 seconds and a drop of ~70 meters (230 feet).

Sniper: One shot, one kill.