我曾经也是学霸同桌
[wŏ céng jīng yĕ shì xué bà tóng zhuō]
The nickname can be translated as 'I was once the top student sitting next to you'. It implies a change from being a diligent, outstanding student in the past to perhaps not so much in the present, or it simply reflects on past school memories, evoking nostalgia for those days and times.