"I have spent many, many hours working for me one moment in time." Serena Williams

i don't really understand, but i think it meas when for example a arobat player performs really good, they took hours and hours to get there. it is like the entertainer, making up new jokes and say it in a funny way so that everyone would laugh. you have to put a lot of effort to be a good entertainer and acrobat or anything that you want to be. You have to laugh everyday, so they would laugh. you have to spent a lot of time, working at one and only one thing like as a acrobat jumping over a fire hoop. it takes a long time to do that, they put effort in it so they trust themselves and do it their best. until they could perform perfectly in front of a crowd of people.