You should say:
what it was
how you made this mistake
when it was
and explain how it affected you.
雅思口語part2高分話題范文參考:
The biggest mistake in my life was falling in love with the wrong girl who had a completely different view of life, love and relationship. I was hardly 17 years old when I fall hard for this girl.
Initially, we were classmates and then became friends. In a year I started to feel something about her that was quite extraordinary and hard to explain. I guess people call this 'love'. My whole world started to shift and I was surrounded by a mirage for this whole time. Not a single moment had passed when I didn't think about her. She was the centre and power source of my universe. When I proposed her, she expressed her boundless joys and acted as if I should have proposed her earlier. So far, this is a sweet and innocent love story of a teenager and I was happy to have her in my life.
However, it took me only a few months to realise that she was not serious about our relationship. When she was my whole world, I was her just another temporary boyfriend. The relationship ended in ten months and I was so broken-hearted that I could not concentrate on anything for a while. My parents also knew about it and they were very supportive of me. First few days, it was quite difficult for me to get back to my normal life, study or go outside. I simply could not appease my mind that I made a great mistake and it was like an illusion that I need to come out from soon. However, when I started realising that I made a big mistake by approaching a serious relationship without even knowing the girl genuinely, I started making peace with my mind. I was completely honest with myself and that eventually helped me to get out of the depressive time I went through at that time.
The lesson learned from this mistake made me more cautious about making any kind of relationship and I am happy that I took this mistake as an event to learn a lesson. However, I often feel bad that how someone could be so naive to play with someone's sentiment so cheaply.