Possible responses:
1. There are 5 books in Tehillim.
2. You should sit in two places.
3. You should stand in one place.
4. You should not finish the whole book of Tehillim.
5. You should be davening, not just saying the words.
6. I have a friend who says the entire sefer Tehillim every day.
7. Maybe you have ADHD.
8. Try saying Tehillim at midnight with a harp to accompany you. Guaranteed to annoy your roommates.
9. It’s also called Tehillos.
10. Why are you trying to say the whole thing at once anyway? Break it up into manageable bits!