It figures Clifton would look to keep things simple with her straightforward title. Here's a hint: we're not talking about bad times here. No, we're talking about "good times," plain and simple. No need for fancy words to prove how clever the speaker can be in coming up with a better way to describe those happier moments. "good times" works just fine.
Since the title is also the poem's refrain, we might also assume that Clifton is keeping with the convention of titling a poem with its refrain. Check out Dunbar and Brooks for more examples of the same technique. Plus, the refrain just so happens to be a popular phrase in most English speaking places, so the title also looks to be setting an informal mood that's oh-so relatable. Because it's a phrase that everyday folks can identify with, the speaker gets to reach a wider audience—one that's not necessarily wearing fancy pants.
And by the end, what's really the point of the whole poem? Why, dear children, to remember those good times no matter how tough things may get. So the title is also a bit of a reminder of what's really important, just in case we missed that refrain.