We always hear about how we're supposed to stay connected with our partners. Just about every teacher we've taken lessons will mention this. And yes, while at a milonga, we'll follow through...for a short period time.
After that, we start focusing on ourselves. Not out of selfishness, but because the perfectionist side of us feels that in order to dance well with another person, we need to first "work on ourselves."
But this is often the reason why a dance might feel stiff, awkward, or fall apart completely.
Connection with our partners isn't just an idea that sounds good while talking about tango. Paying attention to the person we're dancing with has to be happening all the time, and should be the basis on how we execute our form and technique. This mutual awareness isn't just a general act of giving and goodwill, it's also the best source of our creativity, dynamism, and energy.
It's true that we have to make some time for independent practice. But ultimately, tango is an activity where all the benefits of "working on ourselves" only come to light when opening up to others.