pull/haul yourself up by the/your (own) bootstraps idiom
靠自己的努力取得成功，自力更生
to improve your situation without any help from other people
He left school at 15 and pulled himself up by his bootstraps to ultimately head up a company. 他15岁就离开了学校，完全靠自己的能力最终成为一家公司的主管。