I found myself using today’s idiom in a conversation last week. It is to “cross that bridge when we come to it”. It is used to talk about a difficult situation or problem that will happen in the future, but it hasn’t happened yet; we don’t want to think about how to solve that problem yet because it’s still in the future. So in this idiom the “bridge” represents the problem and “crossing” it represents solving it. Therefore this idiom means we will think about how to solve that problem when it happens, but not now. For example:
A: I have to move in September, but I don’t know where I can find a good place to live.
B: Well, you should cross that bridge when you come to it. There’s no point in worrying about it now.
A: Our parents are healthy now, but what are we going to do when they get older and start to become weak?
B: Let’s cross that bridge when we come to it. I’m sure that won’t happen for many years.
A: We have so much to do this week. We have to finish the report and plan the presentation. Also, next week we have to plan a meeting to discuss the budget. Where are we going to have that meeting?
B: Let’s just cross that bridge when we come to it. Right now, we need to concentrate on our tasks for this week.
Right now, I’m still in high school. I don’t know where to go to university, but I’ll cross that bridge when I come to it. I can’t worry about it yet.
So, as you can see from my examples, the word “we” can be changed depending on who is speaking. We always use this expression to talk about the future, but we can’t use it talk about the past. Therefore, it sounds strange to say, “I crossed that bridge when I came to it.”