Invaluable: Without one, it's far too easy to get sidetracked.

其中一项议程是弥足珍贵的：没有一个，这太容易牵制。

He does not let himself get sidetracked by fads and trends.

他不让自己受时髦和时尚东西的折腾。

Don't get sidetracked by technologies or the blog-worthiness of your next feature.

不要因科技或者是博客之类的东西影响了你下一个追求的特性。