"A" is a letter of comfort.
It stands for the first, the best, the one working harder than the rest
"A" means less fears, more cheers, no need for tears
It provides security, gives clarity, justifies any loss of sanity
"A" is for late nights, websites, cheating plights, "it'll be all right"
"A" is everything.

"B" is a letter of failure.
It gives the feeling of falling shorter than you should, doing worse than you could, "you're no good"
"B" taunts you, shakes you, haunts you, breaks you
It causes swollen eyes, lack of pride, the phrase, "well, you tried"
"B" ruins reputations, hands out validation, seals in your appellation
"B" is nothing.