Simpson, 18, who split from the 20-year-old fashionista in May after two years of dating says it was tough conducting a relationship under the public scrutiny, reported Cosmopolitan.
"It was getting so celebrity-oriented that it was kind of scary. But I'll always have the craziest respect for her," he said.
The "Pretty Brown Eyes" says he is currently enjoying his singlehood as he can afford to focus on himself.
"Even if you absolutely adore someone, it doesn't mean they're right for you at that time in your life. Being single is amazing for me right now. I can focus on peeling back the layers and self-growth.