Why did Isaac Newton leave Cambridge and return to Woolsthorpe?

He attended Trinity College in Cambridge, but could not afford it and had to do chores to attend. Soon however teachers and other students began to realize how bright he really was, but just as they were realizing that, everyone had to leave the college due to the plague. You had a better chance of survival if you went back to your home. However, Newton came up with calculus and the three laws of motion while sitting under a tree at the farm, while the sheep were grazing.