I really like this girl that I met, but I am not sure how to really make a strong connection. Many commonalities I find, I never really feel all that connected with her, and then after I always doubt I've accomplished anything really.

she get excited (well over all sorts of things), but also when I state a commonality - maybe that is just it - seems excited that you've found a tenous commonality?

For instance, if she were to say that she likes Star Trek or something, I'll feel a powerful connection and we'll have a vibrant conversational thread.

However if she brings up that she's a dancer (she's danced for 14 years) - I can relate, but I don't feel that bond. Which doesn't matter much, but I want her to feel that bond, strongly, on all commonalities.

So some dialog example:
HB9: I teach dance classes: tap, tango, (blah blah).
RockStarz: AH! I took Salsa classes.
RockStarz: I was embarressingly bad. After a few months of doing it, I got so familiar with the movements my feet were skimming the ground?
My dance teacher said I lacked vitality and had me stand on my toes. Consequently, I'm not a girl, I'm not used to this, so consequently I started leaning forward to compensate? And the teacher, went to the front of the class, clapped her hands and said 'we're going to practice the basic step again today, because RockStarz has the posture of a prawn!'. I was so embarrassed!
HB9: [amusement]
RockStarz: so whats it like teaching?
HB9: [blah blah]

So I want to get a greater feeling of connection out of commonalities, how can I do this?