Unless you are e. e. cummings, the odds are quite good that you usually use capital letters for many things in your writing, but my question is how do you feel about the first letter of each line in a poem? Dropping the first letter to lowercase makes it feel to me as if you are simply talking as you would in a paragraph, and especially if you are rhyming (which as you know I normally avoid like the plague) hopefully keeps your readers from reading each line on its own, as if it had no grammatical connection the line that came before or the one after.
That is all well and good, but has anybody explained this to Microsoft Word? If you don’t want every line after a return to start with a capital, you have to go into some toolbar menu and unclick the default. And of course, with each new (usually worse, less convenient) version of Word, the Byzantine lengths to which you must go to achieve this get more annoying. For this reason, among others, I have been being lazy, and capitalizing.