Think of "throw off" as knocking something off balance. Then you will be able to guess further idioms based on this phrase. I was trying to give a talk but was thrown off by a heckler in the back row. I was focussed on diplomacy but thrown off by the aggressive attack. I was being interviewed on my favourite subject but was thrown off by the attractive assistant in the interveiw room. We were set to travel to Greece but our plans were thrown off by extreme weather.

"throw off" means disrupt e.g. I had a very well planned study schedule but then I broke my leg and this threw off my schedule completely.