Frustrating Paradox of Precedent in Section 30 of Indian Contract Act

Main toh confused hu, kya aap log bhi. Section 30 ke under, precedent ki baat hoti hai. Yeh toh batata hai ki ek contract badla jaa sakta hai, lekin phir se ek doosre sath. Lekin abhi yeh bhi kaha jaata hai ki woh parivartan khatm mat kare, jismein contract badla jaa sakta hai. Par kya hoga jab yeh ek doosra contract ban jao aur isme parivartan karne aur phir se ek doosra badalne ka cycle shuru ho jaye? Main toh samajh nahin sakta ki iske beech kya farq hai.