I had the same experience. I could take a running jump of about 10 feet onto grass no problem. But concrete was impossible. After the third hour of tutorial videos, I realized that I didn't have any abnormal bone or something. My form was just plain horrible, and the grass had allowed for it. After I corrected my form, I had concrete down within the hour.
Re-evaluate your form and maybe try something softer before concrete (wood, thin carpet, etc.)