at/in the back of your mind idiom
在潜意识里，下意识地（觉得）
If something is at/in the back of your mind, you intend to do it, but are not actively thinking about it.
It's been at the back of my mind to call José for several days now, but I haven't got round to it yet. 这几天我一直打算给乔斯打电话，但至今没得空。