O mischief, thou art swift to enter in the thoughts of desperate men!
— William Shakespeare

We enter the world alone, we leave the world alone.
James A. Froude enters quote

Opportunity rarely knocks on your door. Knock rather on opportunity's door if you ardently wish to enter.
— B. C. Forbes

How else but through a broken heart may Lord Christ enter in?
— Oscar Wilde

Teachers open the door, but you must enter by yourself.
— enters quotation by Chinese Proverbs