"Something that makes you feel strong."
It makes sense. When you do something that you are strong at, you should feel stronger after you've done it. If you're a strong presenter, presenting fuels your strength. Strong writer? Writing makes you feel stronger.
Strengths make you feel strong.
So, if that's the case, what's a weakness?
Wait for it...
"Something that makes you feel weak."
When you do a weakness, you feel weaker after having done it. But here's the catch, and it's a huge one:
You can be really good at a weakness.
Remember, a weakness isn't something you're bad at, it's something that makes you feel weak. This means that you could become really good at something and it could still make you feel weak. What's scarier is that you might actually build a career around it.
You'll then wake up one day and realize that you are getting compensated, celebrated, and given more responsibility to do the very thing that makes you feel weakest.
I'm this way with formatting spreadsheets. I'm really good at it -- I just have an eye for stylistically laying out data in a spreadsheet so that it is clean and easy to digest. But I hate doing it. If I don't watch myself, I might accidentally do lots of it and make it a core part of my job.
The key to effective leadership is to do your strengths and manage your weaknesses. This, of course, presumes that you know what your strengths are. The best way to figure out a strength is to track energy.
Energy is the stuff that's released when you do your strengths.
So pick a week, any week, and track what makes you feel strong and energized. Then do more of that. The results will be exponential.