Songfacts®:

• Tom Walker's breakthrough single is based on a friend of his who was struggling with drug addiction. Tom urges his pal to seek help and he will "leave a light on" if and when he wants to talk about it.
  
  If you look into the distance, there's a house up on the hill
  Guidin' like a lighthouse
  To a place where you'll be safe to feel our grace
  'Cause we've all made mistakes
  If you've lost your way
  
  Walker explained to The Sun that his friend "was going through a really dark time and I wrote the song to let him know that he's not alone and I was always there for him."
• Though inspired by Tom's friend, the song has a broader meaning aimed at anyone who has let an addiction of some form get a hold of them. He explained to The Idolator:
  
  "Everybody I know, myself included, at some point in their lives has struggled with some form of addiction, whether it be drinking too much or eating too much. You know, whatever it is, I think somebody at some point has struggled with addiction. I just wanted to write this song for my family and my friends to let them know that we can talk about it."
• Tom Walker co-wrote the song with Steve Mac, who has credits on numerous UK #1 singles and albums for artists such as Westlife ("Flying Without Wings"), The Wanted ("Glad You Came") Clean Bandit ("Symphony") and Ed Sheeran ("Shape Of You"). The pair connected through Walker's A&R at Relentless Records in the UK.
• While Walker knew that Steve Mac is a popular songwriter, he was unaware of the vast extent of his hitmaking resume. He explained: "I didn't really research who I was going in. I was getting in with more and more important people and it was actually making me more nervous going into a session if I read their Wikipedia page. Because it's like, 'Oh my god, I need to perform today. I need to do really well.; I knew what he was about, but I didn't research it in depth."
  
  As a result, Walker was not intimidated by working with such a successful collaborator and they penned this song during their first session in just five or six hours.
• The song was originally released in the UK on October 13, 2017 and at first it was a slow grower in Walker's native land. Meanwhile, it was taking off across the English Channel, rising to the top of France's singles chart in March 2018. It also reached the Top 10 in several other European countries, including Austria, Belgium, Germany and Switzerland. "Leave a Light On" eventually reached the UK Top 40 in May 2018.
• The What a Time to Be Alive title was inspired by a lyric from the album cut "Blessings," not Drake and Future's 2015 collaborative mixtape.