This show is somewhat a quotes bank, so let me start.

"Life is a tragedy in close up and a comedy in long shot"

"Love starts with passion, goes with reality, ends in solidarity. Losing passion doesn't mean losing love." - Episode 12.

"No one tells us how we're supposed to love each other
So it seems we only learn what love is after being hurt and we realize its value only after losing it
That's how we come to understand what's love"

"Some loves are epic tales, and some are short stories. Just because you wrote a short story doesn't mean it's a failure"

"If love is looking at each other, then marriage is looking in the same direction together"

"Rather than growing love, you could say marriage is the process of exhausting it" - Ep 12

"Love is a rainbow. Love shines through a colorful spectrum of emotions. Red is passion. Orange is warmth. Yellow is happiness. Green is peace. Blue is trust. Indigo is depth. Violet is mystique. " - EP 7
 
"Love isn’t just red. The love we once shared just changed into different colors as time passed. But it didn’t stop being love just because it was a different color. " -  EP 7