There's one thing I haven't read yet in the previous answers: after you s**t you still wipe your ass with toilet paper before using the bidet, and you do it pretty well too.
When you get to use the bidet, your butt is already pretty clean, but washing it with a bidet makes it entirely clean and feels really nice.
You use a towel right after using a bidet, which is why you see one hanging right by a bidet in most (if not all) bathrooms with a bidet. This prevents spraying water everywhere after you're clean.
Also, when you use it once, you learn how strong you want your water stream to be, not to wet the whole bathroom. You do the same the first time you wash your dishes (if your faucet shoots water too strongly, you wet the kitchen beyond the sink)
Also: those who use bidet go through a rigorous training to master its practice and transmit it's secrets orally to the next generation.
Bonus: Crocodile Dundee VS a bidet