ATC frustration
sitting at a holding point watching someone join wide on left base on a windy day and having to wait until he has landed when if ATC understood effects of wind on small aeroplanes in circuit other aircraft could easily be despatched but of course they often subscrine to the "all pilots are XXXXXX and it is best to treat them as such even when you may be being a little unfair to the odd one.
or
trying to stay in glide range of the strip behind a baby airline pilot on a cross country circuit outside the ATZ and he being given priority and me having to orbit as spacing compromised as a result - costs me money too
or
pilots report as over VRP when obviously not and not being challenged
PS I am grumpy today!