Have you run head first into a chair and split your skull open? I did (when I was about four).
And even now, I occasionally almost fall over from dizziness. This doesn't have anything to do with my head injury, my sinuses getting clogged can sometimes mess up my equilibrium.
And of course, back during the nightmare month when my psychiatrist was prescribing me Duloxetine for my depression, I was dizzy and falling all the time, due to the fact my eyes lost their ability to dilatate and contract fast enough to accommodate walking from a lighted room into a darkened one and vice versa (and of course, making me more or less sunblind outside on a sunny day).