I know what it is to be in need, and I know what it is to have plenty. I have learned the secret of being content in any and every situation, whether well fed or hungry, whether living in plenty or in want. I can do all this through him who gives me strength.

Philippians 4

I know what it is to be in need, and I know what it is to have plenty. I have learned the secret of being content in any and every situation, whether well fed or hungry, whether living in plenty or in want. I can do all this through him who gives me strength. v12-13

My sense is that v13 is more often quoted than v12, yet v12 I believe is equally important because it clarifies and qualifies the basis for the strength found in v13.  Strength is found regardless of circumstances - changing circumstances (health, wealth, etc.) do not result in strength.  Strength is a constant as it comes from God - who does not change and who is always with us.