the hard way idiom
以不必要的费力的方式
a way of doing something that makes it more difficult than it needs to be
She always does things the hard way. 她做起事来总是费力不讨好。
C2 从吃苦头中（汲取教训）
If you learn something the hard way, you learn from unpleasant experiences rather than by being taught.
If she won't listen, she'll have to learn/find out the hard way. 如果她不听，那只好吃些苦头吸取教训了。