I.
When my love swears that she is made of truth,
I do believe her, though I know she lies,
That she might think me some untutor'd youth,
Unskilful in the world's false forgeries,
Thus vainly thinking that she thinks me young,
Although I know my years be past the best,
I smiling credit her false-speaking tongue,
Outfacing faults in love with love's ill rest.
But wherefore says my love that she is young?
And wherefore say not I that I am old?
O, love's best habit is a soothing tongue,
Compare with  Sonnet 138 ’s 8th line: 
 On both sides thus is simple truth suppressed:
The Passionate Pilgrim: 1