The mental image this phrase generates makes its meaning pretty clear. Forbes defines it “This means to waste time”. That’s not quite the sense I’ve heard it used as in the past.
Investopedia‘s definition comes closer “To undertake an impossible task or project or to make a task or project unnecessarily difficult”, but goes on to give an example I found unhelpful.
To waste one’s time attempting to do the impossible.
Scope is too big to do in one project. Break it up into more than one. Don’t try to solve every problem at once. Identify a couple, address them, and move on.
I hear the “boil an ocean” statement most often when a project hasn’t had the scope of the project defined well or has suffered from “scope creep“, where more and more has been thrown into the project bucket.
I’ve run a number of global roll-outs of tools/platforms/branding. Every time there were a raft of decisions and objections to get through. You can’t be daunted by that. You must manage stakeholders (often changing) expectations and still deliver.
Have the big vision, but define the project scope at a deliverable scale – and stick to it.
That way you won’t need to boil any oceans.