"There is a swelling storm
And I'm caught up in the middle of it all
And it takes control
Of the person that I thought I was
The boy I used to know"

it´s about a relationship that started at a young age and now is going through a crisis and the singer did something or reacted in a way that makes them not recognise themselves.

But there, is a light
In the dark, and I feel its warmth
In my hands, and my heart
Why can't I hold on?

they see hope for, but can´t hold on to it

It comes and goes in waves
It always does, it always does
We watch as our young hearts fade
Into the flood, into the flood

the feelings about the relationship come an go as they "grow up" and lose innocence

The freedom, of falling
A feeling I thought was set in stone
It slips through, my fingers
I'm trying hard to let go

they thought what they used to feel was a certain thing, but now they're suddenly free and having a hard time letting the past go

It comes and goes in waves
It comes and goes in waves
And carries us away

they get better and worse as in waves, but these waves start taking away what they used to have.

Through the wind
Down to the place we used to lay when we were kids
Memories, of a stolen place
Caught in the silence
An echo lost in space

they reminisce about old times, when they were together, but it's just an echo now, because doesn't exist anymore

I watched my wild youth
Disappear in front of my eyes
Moments of magic and wonder
It seems so hard to find
Is it ever coming back again?
Is it ever coming back again?
Take me back to the feeling when
Everything was left to find

they spent their youth together, and now it's over and they're not so young anymore, and don't have that person, and don't know if they'll ever feel something like that again.