Maturing Your Practice
Learning the forms is just one aspect of Taijiquan practice. After you have committed the forms to memory one should stop and take a look as to what has made it into your forms.
Do you have:
Proper structure and alignment
Is the breath being utilized correctly?
Are you utilizing and adhering to the tai chi principles?
Have you expanded your awareness?
Do you achieve a meditative state when you practice?
There are many, many concepts to reflect upon in order to impartially determine what needs to be worked on, incorporated or tossed, so that your forms become better and your practice makes its way towards perfection.
This all takes time and a discerning eye. One should drop the ego and take constructive criticism from people you respect in order to continuously mature your practice.