Is it normal to learn the hard way? Or is it just stupid people who have to go through suffering and a lot of bullshit until they learn. Is it normal to have to learn firsthand even though you know you should stay away? Does this happen only to impulsive or emotional or sensual people only?

Stupid people do stupid things and DON'T learn from the results.
If you're doing the same stupid thing over and over and over again and you're sitting there wondering why your life sucks then I must regret to inform you that you are stupid.