R’ Yehonoson Eibeshutz zt”l (Tiferes Yehonason) would say:
“The Torah is described as a 'סם החיים' - ‘prescription for life’ - a medicine able to purify those who take it. Thus, we are warned not to add nor detract from the Torah’s words - 'לא תוסיפו ... ולא תגרעו'. A prescription drug is a precise mixture of various substances, and changing the proportions can have toxic effects. So, too, are the commandments of the Torah given in the exact and correct proportions, and to change even one single word can have a terrible and deleterious effect.”
A Wise Man would say: “Inevitably, you will face many defeats in life, but never let yourself become defeated.”