Racehorses really know when they lost and they show it after the race is over by stomping around, shaking their head and generally acting mad. When they win they are bigger than life, confident and proud.
Less talented racehorses that just aren’t fast enough or lack confidence in general, also know when they lose and that type will tend to sulk after a race.
Bad racehorses that may be fast enough but they just don’t want to race are the worst to be around because they neither get mad nor sulk, but walk around after the race acting like, “see what I did, I got out of that race without even trying, ha, ha! Why don’t you let me try showjumping?” Believe me, thoroughbred racehorses are pretty smart cookies and every one is unique.