Be honest

Ask yourself honestly why you want to train with a sword...
Because it looks cool?
You have some romantic notion of being a samurai?
You've watched a lot of Highlander, The Last Samurai, Braveheart or Gladiator?
Or are you preserving the heritage? 

Visit other classes

It is easy to assume that your martial art is 'the best' and to dismiss all other arts.
This is also naive.
Have you been to other classes?
What are they teaching? How are they teaching it? How skilled are the students? Is their technical knowledge advanced or simplistic?
Go find out for yourself.

Katz: How do you know all this stuff?

Bryson: Well, there's these things called books. They're like TV for smart people.
(A Walk in the Woods)

Mental framework

Imagine a bookshelf in your mind filled with books, folders, resources and information about taijiquan...
The more densely filled your bookshelf is, the more relevant and useful new information will seem.
You will be able to cross-reference, discern, add to existing knowledge and challenge any preconceptions or misconceptions.
Ideally, your bookshelf wants to be filled with anything and everything that might conceivably have a bearing on taijiquan.

Yielding

Last nights 'yielding' workshop was terrific. Sifu Waller neatly illustrated the scope and value of understanding what yielding constitutes and applying it skilfully.

Everyone felt great.

The session also served to debunk the idea of 'pushing hands competitions' - as we discovered that the adequate degree of physical flexibility on the part of the defender made it impossible for the aggressor to actually push anyone. It was like pushing against water.

We ended with seeking to apply holds, locks and various attacks. All to no avail. Even when the attacker did their level best to mess you up and be non-cooperative and awkward.

Our only enemy proved to be our own physical tension.

Can anything be stupider than that a man has the right to kill me because he lives on the other side of a river and his ruler has a quarrel with mine, though I have not quarrelled with him?
(Blaise Pascal)

Take an interest

Instead of just doing what your teacher tells you to do in class, invest in the Art.
Take a much deeper interest in how the human body operates, Asian history, culture, martial arts in general, biomechanics, fitness, strength, health, nutrition, meditation...
The list is endless.
Don't assume anything. Continually question what you know and find out more.

Context

If you read an article about taijiquan but have no interest in taijiquan - and no foundation knowledge - then your ability to make sense of what you read would be limited.
Most likely you'd quickly lose interest and you wouldn't remember much.
In order to make sense of what you read, you need context.

Consider this: Most people live lives that are not particularly physically challenging. They sit at a desk, or if they move around, it's not a lot. They aren't performing manoeuvres that require tremendous balance and coordination. Thus they settle into a low level of physical capabilities - enough for day-to-day activities or maybe even hiking or biking or playing golf or tennis on the weekends, but far from the level of physical capabilities that a highly trained athlete possesses.

The reason that most people don't possess extraordinary physical capabilities isn't because they don't have the capacity for them, but rather because they're satisfied to live in the comfortable rut of homeostasis and never do the work that is required to get out of it. The same thing is true for all the mental activities we engage in. We learn enough to get by but once we reach that point we seldom push to go beyond.
(Anders Ericsson)

Sick or hypochondriac?

If you are genuinely unhealthy, then don't go to a martial arts class. It is stupid and naive in the extreme. 
If you are a hypochondriac, this is the wrong attitude for martial arts.

The outcome

The quality of your taijiquan is directly proportionate to the degree to which you invest in the Art.
If you are a 'toe dipper' - a tourist - then you will never get very far.
Only by plunging fully into the training can you hope to gain real skill.
An understanding of taijiquan requires commitment, sincerity, humility and a lifetime of practice.

Sickness society

We live in a world where people really enjoy complaining about ailments or comparing medical histories.
Many people engage in this kind of conversation with competitive fervour: eagerly listing their medication and seeking to one-up each other.
Such an attitude has no place in a martial arts class.