‘Bothered’-thinking about it, guilty but never apologises or says sorry.
‘Many THINGS I have done wrong’ things plural so he’s done more than 1 but chooses to talk about this one.
‘Played the handles’ very deliberate action of heating the handles
‘For eternity’ she is marked for life.
‘Thirteen’ immature and naive at 13
Age around 40 male written in 1st person and he’s looking back on life. Written in past tense.

What does the poem remind you of?
Group meeting where you open up about guilty things you may have done because why else would you need to talk about this event that happened a long time ago.
Remind others of bad things they potentially may have done in the past as kids.
Quotes to support
‘I am very bothered when I think of the bad things I have a done in my life’
‘Marked, the doctor said, for eternity’ this is the things that bothers him most.
‘Don’t believe me, please, if i say that was just my butterfingered way, at 13, of asking you if you would marry me.’