And far from easy. And at some point, you're going to be tired. Exhausted. Drained. You'll feel so much pain coursing through, no matter whether you go on or stop to rest. You'll wonder what you're doing. You'll wonder what on Earth you were thinking when you agreed to do this. You'll probably kick yourself for even thinking of it.
But when that happens, remember that it's not the first time you've been there.
And remember that if you can endure and finish what you set out to do, everything will turn out pretty well.