Sonnet LXXVI: Why is my verse so barren of new pride

Why is my verse so barren of new pride,
So far from variation or quick change?
Why with the time do I not glance aside
To new-found methods, and to compounds strange?
Why write I still all one, ever the same,
And keep invention in a noted weed,
That every word doth almost tell my name,
Showing their, birth, and where they did proceed?
O know, sweet love, I always write of you,
And you and love are still my argument,
So all my best is dressing old words new,
Spending again what is already spent:
 For as the sun is daily new and old,
 So is my love still telling what is told.