任何一本词典都不可能包罗万象，如果你在《柯林斯高阶英汉双解词典》上查不到forget doing的用法，你可以查阅其它一些权威词典。如：

I'll never forget meeting my school headmaster for the first time. 我永远忘不了和我小学校长初次见面的情景。《现代英汉词典》

I forgot my father going to London. 我忘记了我父亲曾经去过伦敦。《简明英汉词典》

I shall never forget hearing her singing that song. 我永远不会忘记听她唱那支歌时的情景。《现代英汉综合大辞典》

I shall never forget hearing the President's address. 我将永不忘记听过总统演说的事。《21世纪英汉汉英双向词典》

She would never forget seeing the Himalayas for the first time. 她永远不会忘记第一次看到喜马拉雅山。《剑桥高级学习词典》

I'll never forget seeing my daughter dance in public for the first time. 我永远忘不了看着我女儿第一次当众跳舞的情景。《牛津高阶英汉双解词典》