Like summer's always gonna turn into fall
Like when you don't know the words but you still sing along
Like how when there's thunder, there's lightning too
How the trees are green and the sky is blue
Nothing's gonna change, you and I are inevitable

You didn't even have to say hello
For me to love you till the day I go
I didn't believe in love at first sight
Then you walked in and I saw my whole life
Didn't even have to say hello

'Cause when you know, you know
Shooting stars, fireworks, and desert skies
('Cause when you know, you know)
All my life, I waited for the Sun to shine
('Cause when you know, you know)
Fall in love overnight
Sudden rush, butterflies
Oh, nothing's gonna change, you and I are inevitable

You didn't even have to say hello
For me to love you till the day I go
I didn't believe in love at first sight
Then you walked in and I saw my whole life
Didn't even have to say hello

'Cause when you know, you know
'Cause when you know, you know
You didn't even have to say hello
Didn't even have to say hello
'Cause when you know, you know