被迫长大是指在生活中遇到的困难、挑战和压力使得一个人不得不快速成长、学会应对和适应环境。这个说法可能源于人们的生活经历，例如当一个人在很小的时候就失去了父母，或者在童年时期就被迫承担起家庭的重担。

一些英文例句和中文翻译如下：

"She was forced to grow up too fast when her parents passed away when she was just a child."（她很小的时候就失去了父母，被迫快速长大。）
"After his father's death, he had to take on the responsibipties of the family business and was forced to grow up quickly."（父亲去世后，他不得不承担起家族企业的责任，被迫快速成长。）
"Growing up in a tough neighborhood forced her to mature quickly and learn how to take care of herself."（在一个艰难的社区长大让她很快成熟，学会了如何照顾自己。）