>Adams truly understood that brevity was the soul of wit
Hadn't really twigged that aspect but I think you're correct.
So he combined deep ideas with humour and brevity. He also had to carry his torch post-Hitchhikers, a show which had had creative input from other talented people in addition to his own.
Small wonder he found writing hard. It must have been really really hard.
https://www.youtube.com/watch?v=KqS_ev58MRg#t=2m45s