Do not let minor irritations, resentments and unhappiness ruin your day. Forget it. Now.
Events in the coming days, weeks and months will always seek your attention. Sooner or later you are going to forget all the petty things that annoy you. Why not do it now?
Save yourself unhappiness, forget instantaneously whatever seem to upset you. Your mind naturally does not like bad feelings and will try to get rid of it. Why not help it along?