When my love swears that she is made of truth <br />I do believe her, though I know she lies, <br />That she might think me some untutored youth, <br />Unlearnèd in the world's false subtleties. <br />Thus vainly thinking that she thinks me young, <br />Although she knows my days are past the best, <br />Simply I credit her false-speaking tongue; <br />On both sides thus is simple truth suppressed. <br />But wherefore says she not she is unjust? <br />And wherefore say not I that I am old? <br />O, love's best habit is in seeming trust, <br />And age in love, loves not to have years told. <br /> Therefore I lie with her, and she with me, <br /> And in our faults by lies we flattered be.<br /><br />William Shakespeare<br /><br />http://www.poemhunter.com/poem/sonnet-138-when-my-love-swears-that-she-is-made/