Friends who I've worked on this spreadsheet with have sometimes struggled with it. I think it's about imagining, in detail, what your life looks like when it revolves around a job you love. Think about every single detail. Describe the hours, dress, colleagues, pay, surroundings.
Think about the job itself - the content of the career, or the subject. Do you need to feel passionate about your work?
Then think about what you will actually do. Meetings, phone sales, travelling, research, analysis - what do you like doing? What would an ideal breakdown of these activities look like in a pie chart?
Now think about hygiene factors: pay, pension, freebies, childcare etc. How important are these to you? How much do you want to earn? And how much do you need to earn? Work both out.
How about where the job can be done? Would it mean being in one place, or is it flexible? Do you want to travel abroad and would it enable this? Is working from home important?
There may be other features, like focusing on one subject (being an expert) or many, or a job with high levels of autonomy, or teamwork, or integrity, or its ability to combine with something else? Maybe you really want to work for yourself, get a promotion or manage a team?
And finally how does it fit your strengths you've already outlined?
Work out, in detail a series of criteria which essentially describe your perfect career, and the life it enables. Write them down and weight them according to their importance - try it!