If you spread yourself too thin, you won't be doing anyone a favor.

如果你分散太多精力，也就没有任何帮助了。

They say " don't spread yourself too thin or bite off more than you can chew" .

他们说“不要把要求设得太低，也不要贪多嚼不烂”。

If you spread yourself too thin across too many projects, you won't have the energy required to do a good job at any one of them.

如果你把自己分散在太多的项目上，你就没有精力做好任何一个项目。