It's not a poem, it's a couplet. When books are used, they hate less; It's hard to know what's going on until it's gone through.

a thing is difficult unless it is experienced, which means that it is difficult because it is difficult from the beginning. If you have not experienced it yourself, you will not know its difficulty.

the meaning of these two sentences is to wait until you really use knowledge to regret that you have learned too little. You don't know how difficult it is to do things without experiencing them yourself. It enlightens us that we should study hard and ask questions at ordinary times, and when we really use knowledge, we will not go through the books in a hurry; It takes many times of practice to accumulate experience and do things with half the effort.

Deep feeling:

I usually have to make plans, summarize my work, read notes and write papers ... and suddenly I find that my knowledge is not enough, so I forget my words and want to quote an idiom or famous aphorism, but I just can't think of it; When you encounter problems in teaching, you just can't think of a solution; Students' questions are sometimes speechless ... Only then do we know that we have only scratched the surface when studying, and there is still a lot of knowledge to master.

Many things are difficult only after experience. In life, many people, with their eyes high and their eyes low, can't do big things, and don't do small things. They also judge and make irresponsible remarks. They usually feel that they can do anything, but they are helpless when they do it.

So you should do things yourself, explore and practice with your own brains, so that you can understand the essence and truth of things. If you want to succeed in your career, you must work hard and pay hard. As the saying goes, "no pains, no gains" and "no pains, no gains".