“I would like to improve in every facet of my life. No matter how much I may excel at a particular skill or task, I believe I can always get better, and would like an opportunity to gain new experiences that will help me become better at anything I undertake. Does your company offer any extended training courses that I can take advantage of?”
Here you turn it around on the interviewer, making it a question about what they offer rather than a question of what you are bad at. Remember, a standard “biggest weakness” answer as described multiple times on this and other websites is an acceptable answer, but you may also use an answer like the one above if you like