look back on ，表示回首，例如：

1.Now I can look back on the whole tragedy from a distance of forty years.时隔40年后，现在我可以回顾整个悲剧了。

2.I can look back on things with a clear conscience. I did everything I could.我可以问心无愧地回首过去，我已经尽力了。

3.They can look back on their endeavours with pride.他们可以骄傲地回首过去付出的努力。