What does きた do in this sentence


What is the difference between

> 中学生になってもずっとボーッと **生きてきた** けど

> 中学生になってもずっとボーッと **生きた** けど

What does **きた** do in this sentence this is from the second episode of the
anime _K-On!_ the character is telling a story about her school life I don't
see what **きた** does in the sentence.




It adds the sense that the action/state of the preceding verb (生きる) has
continued till now.

If you want to say you will continue living that way into the future, you can
say ずっとボーッと生きていく.

