What do you mean by "the past is hard to remember"

"The past is unbearable" means: unwilling to recall those unpleasant things in the past, unable to bear the pain of memory.

"Look" means yes, yes.

"I can't bear to look back" comes from Yu Meiren in the southern Tang Dynasty;

When is the spring flower and autumn moon? How much do you know about the past? The small building was easterly again last night, and the old country was unbearable to look back on the moon!

Carved fences and jade bricks should still exist, but Zhu Yan changed them. How much sadness can you have? Like a river flowing eastward.

It means, when will the year end? How much do you know about the past? Last night, the spring breeze blew from the small building. How can I bear the pain of missing my hometown in this bright night? Carefully carved railings and jade steps should still be there, but the people I miss are aging. Ask me how much sadness I have in my heart, just like this endless spring water rolling east.

Extended data:

"The small building was easterly again last night, and the country could not bear to look back at the middle of next month." If you drag out an ignoble existence, the spring breeze blows again and the spring flowers bloom again. Recalling the Southern Tang Dynasty and Li's hometown-the old country died early. The poet lives in a prison house, listening to the spring breeze, watching the bright moon, touching the scenery, feeling sad and unable to sleep at night.

Li Yu (937-978) was the queen of Southern Tang Dynasty. In 96 1-975, the country was defeated by the song dynasty. Later he was poisoned by Song Taizong. Although Li Yu is politically incompetent, his artistic talent is extraordinary. "The past is unbearable" shows that this situation has happened many times, and this kind of mental pain is really unbearable. ?

References:

Baidu Encyclopedia-When is Spring Flower and Autumn Moon?