The seed falling among the thorns refers to someone who hears the word, but the worries of this life and the deceitfulness of wealth choke the word, making it unfruitful.
Even though I believe in Jesus Christ as my Savior, I still have thorns in my life that distract me from spreading the Word of the Lord. Call them excuses, if you must. Whenever we give anything else top priority, we are cheating ourselves along with dishonoring God. The one thing that you never want to be greedy with is God's Word.