Meaning:
“厉害了” is roughly equivalent to the exclamation “You’re good!” “我的哥” is literally translated as “big brother.” The saying first arose when a middle school student was caught playing the online game “Glory of the Kings” (王者荣耀) during a military training. The drillmaster caught the kid playing the game and then helped him finish the game with top scores, leaving the other players in admiration and awe. They all exclaimed, “You’re good, big brother!” The saying quickly went viral online with derivatives like “厉害了我的姐” (You’re good, sister). The latter half of this saying can be either a person or a thing that is extraordinary.
Example:
A: 你的论文写完了吗?怎么溜出来看电影?
Nǐ de lùnwén xiě wán le ma? Zěnme līu chūlái kàn diànyǐng?
Have you finished writing your paper? How come you have slipped out to watch a movie?
B: 上个星期就写完了。
Shàng gè xīngqī jìu xiě wán le。
I finished writing the paper last week.
A: 厉害了我的哥!
Lìhàile wǒdegē!
You’re good, buddy!
(Edited by Stephanie Yang)