I used to know someone who constantly surprised me by their lack of motivation to do anything. To go out, to work hard, have dreams, try, do, any of those type of things that involve stimulus or drive. Their lack of inspiration, inspired me, and for that, I am thankful. This is Lackluster.

dull and boring
uninspired & unmoved
bland and down
uninteresting & unconcerned

spiritless and square

for a matter of fact

that's just you