Hey - everyone needs to just topple over sideways while not moving at least once in life, but hopefully only once. My two crashes since I started commuting were both the result of underestimating the angle or hop it took to get the front wheel up onto the sidewalk. Once the first week of a new bike with thinner tires, trying to get to where I could hit the crosswalk button at an intersection which requires that. Went down pretty fast and hard. The other time I was "squeezed" up onto the sidewalk by a cager. It was slow and no big deal. I'm hoping I've learned just how easy it is to get a tire caught in a groove!