inner strength

Where does it even come from except for some kind of core that no mortal can be fully aware of. It must be comprised of the sum total of experiences so a happy life or a challenging life can feed your core so long as you never give up.

Inner strength could also come from a belief or conviction. For example I do believe that one day I'm going to be okay and I look forward to it and treasure that thought as an expectation. That's a big thing in my life, going through so much etc.