I tried but I can't keep my mind off 
The man on the train last night
Something about him is curiously
Charming my heart

Wearing his hat low
His collar up high
Is he tricking me?
Why didn't I go and ask him
To give me a light?

He's on my mind
All the time
Mr. Mystery
He's in my heart
And I don't even
Know who he is

He's not the kind
You usually find
Mr. Mystery

He's in my heart
Tearing me apart
All the time

When I go walking
Through crowds on the street
I feel his ???
Thinking and hoping
We'll be side by side
Some day

Tossing and turning
I can't stop this yearning
To hold him tight

Why didn't I go and ask him
To give me that light?

He's on my mind
All the time
Mr. Mystery
He's in my heart
And I don't even
Know who he is

He's not the kind
You usually find
Mr. Mystery

He's in my heart
Tearing me apart
All the time

He's on my mind
He's on my mind
Mr. Mystery

He's in my heart
Tearing me apart
All the time

He's not the kind
You usually find
Mr. Mystery

He's in my heart
Tearing me apart
All the time

If you have any clarifications for the lyrics, particularly line 29, let me know in the comments.