Add spaces: InthosedaysyouwheretakenasabigidiotifyousaidanythingelseexceptthatReaganwasabigidiot.

Answer: In those days you where taken as a big idiot if you said anything else except that Reagan was a big idiot.

Add spaces: In1922Courantpublishedabookonfunctiontheory.

Answer: In 1922 Courant published a book on function theory.

Add spaces: Comingfromapoorfamilyhehadtofindawaytosupporthimselffinanciallythroughhisuniversitystudies,soheworkedasaclerkfortheinsurancecompany.

Answer:
Coming from a poor family he had to find a way to support himself financially through his university studies, so he worked as a clerk for the insurance company.