i梦想起航i青春奋斗
[i mèng xiăng qĭ háng i qīng chūn fèn dòu]
This username combines the ideas of starting out (‘启航’, setting sail) and working hard during one's youth ('青春奋斗', struggle of youth). It expresses hope, aspirations, and the dedication needed to realize a big dream at a young age.