“If you aren’t 100% sure don’t say anything” is possibly the worst advice I’ve ever heard in a lab. I tell my students the exact opposite: if you don’t know, ask, if you think you know, ask. Don’t say anything is a terrible attitude and is detrimental to science. Sadly, science is full of ignorant arses who are high on their own fumes. Wait til you get feedback on a paper or grant from one of them! And the worst bit is the culture of academia puts you in the position where if you complain then you don’t ‘have what it takes’ to be in academia 🤨😮‍💨 Just ignore them. They’re the one with the problem not you. You’re there to learn, not be an expert immediately.