are all hard to understand concepts bad concepts? are hard concepts from math and science bad concepts? should we discard calculus? is potty training a toddle

are all hard to understand concepts bad concepts? are hard concepts from math and science bad concepts? should we discard calculus? is potty training a toddler a bad concept? they initially struggle with it and some find it hard is a healthy diet a bad concept? people without prior knowledge of what's healthy and what isn't are likely to struggle