A loose thread asks for attention while the repair is still small.

Small failures announce themselves before they become large ones. A thread, a drip, a rattle, a remark somebody makes twice: at that stage the fix takes minutes, and the only reason to postpone is that nothing is urgent yet. Urgency arrives later at a much worse price. The warning is not the problem, it is the cheapest version of it.

Pick the one loose thread you have been walking past and deal with it today, even badly. Ten minutes now buys back an afternoon later. The same holds for the conversation you keep meaning to have while it is still a small one.