why did buffy always act like being a slayer was such a bad thing when really it was pretty awesome

For one, her destiny is already decided. Many times she was told she was supposed to die. Being told that you are going to die is pretty spooky. Besides that her friends were in danger because of her. She fell in love with a vampire that she knew she could never live a full life with, had she not been the Slayer she would most likely never met Angel.

Being a Slayer can has it advantages, but it has alot of responsibility. The girl literally had the worlds fate on her shoulders on more than one occasion.

Well... She loves saving The Wolrd and Being the good guy but she knows that even though she has friends that The Dicicions she has to make are for her and her alone, she also hates that her job puts innocent people and her friends in danger and gets them killed (Tara, Jenny.ect.).

i hope this info helped you ;D

During the movie she was told she was to be alone, what her life was to be because she was the chosen. When Buffy moved to Sunnydale she didn't want to be the slayer anymore. She just wanted to be a kid with a real life. She wanted to go out, worry about boys and do what sixteen year olds do. As time goes on she takes slaying as a job and things that she has to do. Kendra tells her its a privilege to be a slayer. Buffy finds out that their are rules and a slayer book. Buffy wants to protect her friends so she starts to do things on her own without help. The second time she died she was in heaven and felt she earned he happiness. But was torn out from heaven to back to Hell again. Her relationships are about men who leave her no chance for her family or happiness in life. Her destiny is to save the world but she knows the real world has other responsibilities but she's always in the mystical world killing and protecting the innocent!!!