'Ronan' is a song written by Taylor Swift for Ronan Thompson who died in 2011 due to cancer.  He was only 3 years old. The song was made more emotional when she shared that her mom Andrea has been diagnosed with the big C just last April. The multi-awarded singer chose to perform the song because Maya Thompson, Ronan's mother, was in the audience. It was only the second time Swift performed the song in public, and the whole arena was feeling the emotions. 

Daily Mail reports that Thompson co-wrote the song. She posted on social media, 'this will forever be one of the most special moments of my life. Thank you @taylorswift for your beautiful heart and for never forgetting my Ro. I love you to the moon and back.'

Thompson used to have a blog, 'Rock star Ronan',  journaling her journey as a mother with a son diagnosed with cancer.  Swift would read it every night.  When the child died days before his 4^th birthday, she wrote the lyrics based on the actual quotes from the online journal of the mother.

All sales from this single, 'Ronan' went towards cancer research. The chorus ends with the line, 'you were my best four years'.

Last April, Swift went public about the struggles of her own mother against cancer. She posted on social media:  'She wanted you to know because your parents may be too busy juggling everything they've got going on to go to the doctor, and maybe you reminding them to go get checked for cancer could possibly lead to an early diagnosis and an easier battle..." she added. "Or peace of mind in knowing that they're healthy and there's nothing to  worry about. She wanted you to know why she may not be at as many shows this tour. She's got an important battle to fight.'