Learn English – Adjective to describe someone who is knowledgeable, resolute, and calm

I have a situation/feeling that occurs to me frequently and I'm not sure what the adjective is to describe it (or if there even is one). I'd love to hear your ideas on the matter.

The situation is one where I feel like I have some general knowledge, typically gained through experience, that lets me look at a situation more clearly and then take some action (or at least know what action to take) in a positive direction.

Here are some examples:

1. My young children frequently argue over who gets to sit in the middle seat at a three-seat table during dinner. As an adult, my viewpoint on who-sits-where is that it makes no difference in the grand scheme of things. The seat can be shared by each person over multiple nights, etc. It's a viewpoint my kids simply don't have the life experience to understand, so I usually just decide and tell them what to do. On my part it's an emotionless decision.

2. Today I have a whole lot of work ahead of me. I'd like to leave by 3pm and go enjoy the sunshine, but it just isn't going to happen. I know that to get everything done I'll probably be working until 10pm. I'm fairly emotionless about it. I could say I'm resigned to the fact that I have to work, but resigned implies some despondence, which I don't feel. What I really feel (based on experience) is that I just have to do it and I'm neither happy nor sad about it.

I'd love to use the word circumspect because it combines what feels like a circle and introspection, but of course that word means something else unrelated.

Sangfroid is not quite right, because there's no precondition for a difficult or dangerous situation.

Other words like stoic or resolute have the emotional content right, but don't convey the implication of experience that underlies the decision. They also tend to convey a hard edge to a way of thinking. I want the connotation to be softer, like chill or calm.

Guru might describe the type of person, but is a noun and is generally too broad. I'm thinking more of a situational word.

So what do you think?