I think also for many of us we suffer a pervasive sense of panic and fear but have no reason for it, its not anything tangible. The best help Ive had with that (apart from anti anxiety meds when needed, dont need them now) is that these feelings can be managed, dealt with, navigated through, worked alongside. Children wont know this if they're just expected to be reactive to it and not develop skills to work with it to minimise its effect.
Its not about 'not worrying' its about recognising the feeling but having strategies to mean that feelings are not the sole driver of behaviour.
The best counsellor I ever had said 'feelings are not always reliable'. Changed my life.