We hate to break it to you, but Cummings isn't really too into titles. In fact, most of his poems don't appear with titles in their original editions. Just like Emily Dickinson's work, Cummings' poems are usually referred to by their first lines just to make things easier for readers like us to figure out which poem we're talking about.
So perhaps the better question would be, "What's up without the title?" And the answer to that is slightly more interesting. The poem just dives straight in to the sonic repetitions and beautiful imagery that will repeat and modulate throughout the rest of its structure. Think about it: we get the speaker ("my"), the object of his affection ("my love"), and the action to follow ("went riding"). This is no "Once upon a time" set-up. We're off and running from the very start, thanks in no small part to this first line.