The greatest crops are grown not just with water and sunlight, but with patience and dedication.
So given a Time Turner, I would tell my 21-year-old self that personal happiness lies in knowing that life is not a check-list of acquisition or achievement. Your qualifications, your CV, are not your life, though you will meet many people of my age and older who confuse the two. Life is difficult, and complicated, and beyond anyone’s total control, and the humility to know that will enable you to survive its vicissitudes.
The danger is not that we will be deprived of speech, but that we will have nothing worth saying.