Answer:
Smile Now, Cry Later means walk away at the end of your day feeling good about what you've done with your life. Live your life without Sadness and keep looking forward.
Smile Now Cry Later is also an old song by Sunny Ozuna that people used to listen to back in the day and when they would go to prison they got it tattooed on them to remember to smile now and stay tough in prison and cry later when they get out.