Hello,
It is very boring ( well for me ) the thoery in my point of view. but if you think at it as if i can pass imgaine all the things i can acieve towards, eg. Grade 6+ it is good. and in my opinion it is handy to know about the some of the things in a thoery that you shouldn't really forget. my teacher still tests me now and then so i won't really forget.
If you are really bored of thoery then you could always take up another instrument or something.. i did i took up the gituar and plays it i stopped after grade 6 because my parents didn't think i put enough effort in it. i also wanted to start a clairnet but they didn't think that i'd play that all the time.
hope that helps