Learning is like sailing against the current. It is Liang Qichao's famous saying that if you don't advance, you will retreat.

If you sail against the current, you will retreat. It means sailing against the current. It is a metaphor that if you don't work hard to move forward, you will retreat. It is also a metaphor that there is resistance in doing things and you must work hard. Source: Qing Liang Qichao's "Speech on the Welcome Meeting of Ticket Merchants in Shanxi": "The husband is old and can keep it, and it is already gone! However, I think that being in the world is like sailing against the current. If you don't advance, you will retreat. "