Building up walls or boundaries?

This is partially personal experience partially collected stories of my friends. Have you heard a phrase “I loved her so much and it hurt even more, I don’t want that any more”? Ok happens to the best of us. But what if after it’s all over you continue guarding yourself from any possibilities? With a rise of psychological awareness people began using tools against toxic people, guarding themselves from any feelings and emotions. But isn’t this more about fear then actually required defenses. You cannot walk through life and never feel any pain, experience anger, be frustrated, breakdown. Sheltering yourself in defenses doesn’t make you happy, it only makes you scared- what if I fail at being a perfect human? What if I miss a hit and get hurt.
One of the exemplary stories, that I have heard recently is about a guy who’s been living his life, dated, had a long term relationship with a girl, with her own problems. When they broke up the guy went on a sabbatical and stays that way, searching for unicorn girl- the perfection, so he can be safe. True fact is that he can find a flaw pretty much in anyone, and wont accept a little fact- no one is perfect. Worst of all, he denies himself a right to go for someone he likes, defending himself with work. Right, how long will he last I wonder. Probably really really long. Maybe a life time.
So my point is, the longer you believe that you will suffer the same way in a new relationship, the longer you hang in fear, hold on to anger and old grudges instead of working through them, linger in old memories, the longer you will stay alone and in pain. The moment you let your control go, even for a slightest bit you will see that there can be happiness, and love and good strong relationships. Yep, you have to work to have one, its not a romantic comedy where everything is easy and directed. But when you have a person who is ready to invest the same way you do, ready to be a grownup and accept the responsibility, that’s the moment when you have a healthy relationship.
Have an awesome day guys.