To borrow trouble is to contract a debt that any man is better without. If your troubles are not borrowed, they are not likely to be many or great.

I used to hear a saying
That had a deal of pith;
It gave a cheerful spirit
To face existence with,
Especially when matters
Seemed doomed to go askew,
'Twas Never trouble trouble
Till trouble troubles you.

Not woes at hand, those coming
Are hardest to resist;
We hear them stalk like giants,
We see them through a mist.
But big things in the brewing
Are small things in the brew;
So never trouble trouble
Till trouble troubles you.

Just look at things through glasses
That show the evidence;
One lens of them is courage,
The other common sense.
They'll make it clear, misgivings
Are just a bugaboo;
No more you'll trouble trouble
Till trouble troubles you.

St. Clair Adams.