Types of Bullies
It's a combination of several different factors at work (not necessarily all of them):
- Learning things the hard way
- Repeating scenarios to find catharsis
Learning Things The Hard Way
Most people have to learn things for themselves, rather than following instruction. This especially is the case for emotionally involved situations (such as love), but can apply in any situation. For a neurocognitive basis for this, some people are predominantly No-Go learners, whereas others are Go learners; this predisposition is genetic, and affects dopamine expression in the reward centers of the brain.
No-Go learners respond best to negative consequences; Go learners respond best to positive outcomes. Someone who always learns the hard way might be a No-Go Learner.
Nothing will make you keep hitting your head against a brick wall like being fixated/obsessed by someone/something. It'll encourage tunnel vision, and make you lose sight of the big picture and get lost in the details.
Repeating Scenarios To Find Catharsis
People have a tendency to repeat traumatic events in their lives so that they can change the outcome of that experience - or at least process it. This may cause someone to keep acting out seemingly strange behaviors, which lead to a negative conclusion - until they can break the cycle (or find a safe way to discharge the emotional payload and process it).
This is particularly common in people who have PTSD and may be tied to specific circumstances, or anniversaries of events - even if they're not consciously aware of the connection.
Maybe they're just not paying attention to what they need to be to help them? You should probably give them a nudge in the right direction.