Think of the most versatile and time-saving tool in your shop--the one tool that you use for every project, the one you'll only give up "when you pry it from my cold, dead hands." Maybe it's your table saw. Maybe it's your set of planes or chisels. For the sake of discussion, let's limit this to a tool with a metal blade or bit that nobody would buy if it weren't for its ability to cut wood (so, for example, you don't have to get rid of your workbench or clamps, or even your drill--because a drill is also often used to drive screws). Now:
What tool (or general class of tool) is it, and what would it take for you to give it up? (no cheating and saying you will never give it up, that you'll only give it up if you're forced to quit woodworking, etc.)
How would this affect your woodworking process and the end products? Would you be able to work as efficiently? Would you have to relearn how to do a lot of things? How much longer would it take you to complete your projects? Would the quality of your end products change?
Would you still be able to easily work on all your projects with the tools you already have? What tool(s), if any, would you need to buy to replace its functionality? (You can't buy or use the same or very similar type of tool--for example, if you gave up your track saw, you can't use or buy a new track saw or circular saw.)
Would you continue to work on the same types of projects, or would you change the types of projects you work on to better fit the tools you can still use--for example, would you explore a different branch of woodworking that you hadn't done before, like turning? Would you switch from primarily using power tools to hand tools, or vice-versa?
Would you get less, the same, or more satisfaction out of your projects as a result of any or all of the above? Why?