Lift up your hearts!
No more complaint and fear! It well may be
some happier hour will find this memory fair.

[Revocate animos, maestumque timorem
mittite: forsan et haec olim meminisse iuvabit.]

Virgil (70-19 BC) Roman poet [b. Publius Vergilius Maro; also Vergil]
Aeneid [Ænē̆is], Book 1, l. 202ff (1.202-203) (29-19 BC) [tr. Williams (1910)]
    (Source)

(Source (Latin)). Alternate translations:

Resume your courage and dismiss your care.
An hour will come, with pleasure to relate
Your sorrows past, as benefits of Fate.
[tr. Dryden (1697)]

Resume then your courage, and dismiss your desponding fears; perhaps hereafter it may delight you to remember these sufferings.
[tr. Davidson/Buckley (1854)]

Come, cheer your souls, your fears forget;
This suffering will yield us yet
⁠A pleasant tale to tell.
[tr. Conington (1866)]

Recall your courage ; banish gloomy fears.
Some day perhaps the memory even of these
Shall yield delight.
[tr. Cranch (1872)]

Recall your courage, put dull fear away. This too sometime we shall haply remember with delight.
[tr. Mackail (1885)]

Come, call aback your ancient hearts and put your fears away!
This too shall be for joy to you remembered on a day.
[tr. Morris (1900)]

Fear not; take heart; hereafter, it may be
These too will yield a pleasant tale to tell.
[tr. Taylor (1907)]

Recall your courage and put away sad fear. Perchance even this distress it will some day be a joy to recall.
[tr. Fairclough (1916)]

Call the nerve back; dismiss the fear, the sadness.
Some day, perhaps, remembering even this
Will be a pleasure.
[tr. Humphries (1951)]

Take heart again, oh, put your dismal fears away!
One day -- who knows? -- even these will be grand things to look back on.
[tr. Day Lewis (1952)]

Call back
your courage, send away your grieving fear.
Perhaps one day you will remember even
these our adversities with pleasure.
[tr. Mandelbaum (1971), l. 281ff]

Now call back
Your courage, and have done with fear and sorrow.
Some day, perhaps, remembering even this
Will be a pleasure.
[tr. Fitzgerald (1981), l. 275ff]

So summon up your courage once again. This is no time for gloom or fear. The day will come, perhaps, when it will give you pleasure to remember even this.
[tr. West (1990)]

Recall your courage
And put aside your fear and grief. Someday, perhaps,
It will help to remember these troubles as well.
[tr. Lombardo (2005), l. 238ff]

Call up your courage again. Dismiss your grief and fear.
A joy it will be one day, perhaps, to remember even this.
[tr. Fagles (2006)]

Perhaps one day it will be a joy to remember also these things.
[tr. @sentantiq (2011)]

Summon your spirits back, and abandon your sad fear:
perhaps one day even these things will be a pleasing memory.
[tr. @sentantiq/Robinson (2015)]

Perhaps one day it will be a joy to remember even these things
[tr. @sentantiq (2016)]

One day we’re going to look back on even this and laugh (maybe).
[tr. Tortorelli (2017)]

Perhaps someday it will bring pleasure to recall these things.
[tr. @sentantiq (2020)]

Be brave, let go your fear and despair.
Perhaps someday even memory of this will bring you pleasure.
[tr. Bartsch (2021)]

Commentary on this passage: A Hope for Better Days to Come – SENTENTIAE ANTIQUAE.