Because she is a spark of hope in the darkness. She is sunlight on a summer day, and snowball fights on a winter evening. She is a good book by the fire and a hot bath after a long day. She is love and kindness and warmth. She is righteous anger and a blazing flame of loyalty. She is knitted sweaters and thick socks. She is autumn leaves and blooming flowers. She is James' cologne and Library books. She is Lily Evans.
Because he is a hearty laugh in hopelessness. He is stars on a summer night and strong wind on a blustery winter mourning. He is wind against your face and Firewhiskey in your throat. He is laughter and loyalty and fun. He is endless joy and relentless anger. He is ruffled hair and a loosened tie. He is icy hail and a gentle warmth. He is freshly mowed grass and broomstick oil. He is James Potter.
Because their summers are filled with endless days of picnics by the lake and whispered secrets. Of Quidditch pitches and half-hearted revision. Of thousands of plans for the future and more and more ridiculous baby names ("I still say Elvendo-" "JAMES NO!"). And they know that the real world is full of hatred and darkness, and shouted spells in a dark warehouse and its brother against brother and friend against friend, but they can dream. They can dream about their little cottage with a white fence and toy broomsticks scattered on the floor, as their three children play in the back garden, full of flowers.
And as James Potter falls to the floor, he barely has time to realize that he is falling over his son's toy broomstick, and the fact that the petals are falling of the rosebush in their garden and how he never got round to fixing the fence. And when Lily Potter jumps in front of the death sentence heading towards her son, she barely has time to remember golden glow of their youth, and the beautiful, hopeless dream they shared, and how, against all odds, they managed to achieve. James Potter dies with love in his heart and Lily Potter falls with a smile on her face.
And their legacy lives on with a boy with the same dark, messy hair and a girl with the same bright, burning passion, who live in their own cottage, with a white fence, and three children playing Quidditch on toy broomsticks, in a garden full of flowers.