Your mental state can reduce your capability to ride safely. There are plenty of studies to show that drivers under heavy stress are more risky on the road than other drivers. You should approach operating any vehicle very cautiously if you are upset, distraught, or angry. Otherwise, you may prove that things can, indeed, get worse. The upsetting event may be a driver who almost flattens you. Instead of conveying your anger to the transgressor, it's better to let it go and concentrate on your own situation. I knew a motorcyclist, who, after dodging one of these inattentive morons, would remark to himself something like, "He's probably no good in bed, either." That seemed like an effective and amusing way to dissipate the anger quickly.