Every human is born with around 50 to 80 brand-new mutations that arose in the egg or sperm they came from. Most have no effect. They come mainly from the father, and their number rises with his age, because the cells that produce sperm keep dividing throughout life. You are, quite literally, a new edition.
Every day, your kidneys filter around 180 liters of blood plasma, about a bathtub's worth. Yet you only have about 3 liters of plasma, so it passes through your kidneys some sixty times a day. Over 99% of the filtered water is reabsorbed, leaving just one to two liters of urine.
A 70 kg adult is made of about 7 × 10²⁷ atoms, or seven billion billion billion. The observable universe is thought to hold on the order of 10²² to 10²⁴ stars. Even with the high estimate, you contain thousands of times more atoms than there are stars in the entire visible cosmos.