Teens, do you ever quit your job within a season despite the fact you promise to work for a year or more? Why?

I'm wondering if this ever happens to you, or anyone... Well yeah, I'm thinking about working at Target just for the whole summer but they might want me to work for them for a year or more... I'm planning to work from middle of June to middle of August and I will want to politely tell the boss that I quit; however, I wouldn't want to make them extremely angry at me.. So teens, how would your boss feel if you automatically quit your job within a season even though you promise to work for a year or more? Do you even have a problem doing that or no problems at all?