Lose sight of something:
To forget about an important idea or fact because you are thinking too much about other things.
“Lose sight of something” 的意思是 “忽略、遗忘做某件事情”，而忽略的原因多是因为对其它事情想得太多。
例句
We’ve lost sight of what we set out to achieve.
我们忘记了当初想要实现的目标。
You mustn’t lose sight of your goals – keep practising.
你一定要勿忘初衷，坚持练习。
Don’t lose sight of the company’s mission – to serve our customers.
不要遗忘公司的使命，即为客户服务。
