What are the hardest things to do in life?
生活中最艰难的事是什么？

获得20.9k好评的答案@Shikhar Agarwal

To decide whether to "move on" or "try harder".
决定是“过了不提了”还是“更加努力”。

获得5.9k好评的答案@Sudhir Suvarna

Quit a well paying job to pursue one's dreams.
辞掉高薪工作去追寻自己的梦想。

Apologize to people you have hurt.
向你曾伤害过的人道歉。

Accepting one's own mistakes.
承认自己的错误。

Staying positive when you have lost everything you ever had.
拥有过的一切都轰然倒塌时，依然乐观向上。

Living away from family.
离家生活。

Bouncing back when you have hit rock bottom.
当你坠入人生低谷时重新振作。

Making others smile when one has not smiled for ages.
让一个很久没有笑过的人笑出来。

Keep a low profile despite being extremely knowledgeable about his/her profession.
尽管在自己专业相关领域知识非常渊博，却仍能保持低调。

And finally,
最后，

Attending a loved one's funeral.
出席所爱之人的葬礼。

I have done all of the above.
我做过以上所有事。