I can do all things thru Christ? What does that really mean?

Read entire context of this often quoted scripture

Finally, brethren, whatever things are true, whatever things are noble, whatever things are just, whatever things are pure, whatever things are lovely, whatever things are of good report, if there is any virtue and if there is anything praiseworthy—meditate on these things.
9 The things which you learned and received and heard and saw in me, these do, and the God of peace will be with you.
Philippian Generosity
10 ¶ But I rejoiced in the Lord greatly that now at last your care for me has flourished again; though you surely did care, but you lacked opportunity.
11 Not that I speak in regard to need, for I have learned in whatever state I am, to be content:
12 I know how to be abased, and I know how to abound. Everywhere and in all things I have learned both to be full and to be hungry, both to abound and to suffer need.
13 I can do all things through Christ who strengthens me.