is there a high chance of ruining my system ? and why people tell me wait for 21 years old and some say wait for 25 some say wait for 30, i don't understand, i should wait 1 or 10 years, also if i do perfect cycle as u guys wrote me, is there still a chance of getting injured ? i mean a lot of people in my age do it, and finish pretty well, why i should have problems ?:/