Always content, never complacent. There's a fine line between the two, but a little line makes all the difference; a line that is grounded in your intent, in your motivation, and in your aspirations.
Webster's Dictionary defines the word "content" as an adjective meaning "in a state of peaceful happiness." The key words here are "peaceful" and "happiness". To be content is to recognize your current state, position, circumstances, for exactly what they are. CURRENT. Contentedness resides within the moment. To be content is not to be dissuaded from going after loftier ventures should you choose to do so, but rather, to be happy in the waiting, peaceful in the pursuit. I understand contentedness to be joyful and fulfilled in the current moment with your present circumstances, regardless of what the future may hold.
Complacency, on the other hand, in my opinion, is the most dangerous place one can find themselves. Because, in complacency there is no room for growth. Webster's Dictionary defines "complacent" as "showing smug or uncritical satisfaction with oneself or one's achievements". Honestly, just reading this definition makes me fear falling into complacency, because it sounds awful. Uncritical satisfaction in itself, from the standpoint of ambition, is unwise. How can you truly know if you should be rightly satisfied with your circumstances, if you have been too smug to critically analyze the situation in order to ascertain whether or not it is truly constitutive of success? To be complacent, to me, is to be stuck, to be in a rut. But even more than that, to be stuck in that rut with no intention or motivation to get yourself out. Complacency completely stunts all potential for growth, for challenge. Complacency is a danger zone for anyone who wishes to achieve their goals. Complacency is the enemy of greatness.
So is it really possible to be content for a long time and not cross over into the territory of being complacent? I believe that it is. I believe that it is all in the mindset. Like most things in life, the balance between the two is a choice. Do you choose to find joy in the still moments or do you disregard them? Are you choosing to be present in your current reality because you recognize that even life's seemingly dull moments have something to offer? Or are you not present, but rather just accounted for in your current reality because you have stripped yourself of the ability to move forward simply because you refuse to do so?
To choose contentedness is to choose growth, promote peace, and cultivate joy. The choice is yours.