Like his hairbrained, unquenchable youth, bright with folly, the sunsets and vanity lay in the past.

And the first and fundamental cause of your failure is, I think, your hairbrained, unquenchable youth.

This holiday excursion of a hairbrained youth was as transient as a border-foray on a large scale.

A thousand things may happen if you carry out this hairbrained scheme of yours.