like you said, some of that is normal for everyone. there are a lot of factors that can cause a person to experience time going by slow, fast, or feel like it's not real, people around them aren't real, etc. there are also times where high stress or boredom even or depression can cause similar types of experiences.

even if a person isn't sleeping enough or isn't eating enough or is dehydrated, etc., those are also factors that can cause certain experiences in a person.

i have had anxiety issues as well as panic attacks and episodes of agoraphobia throughout my life. as i have gotten older, a lot of that has lessened for me. but even when i did have them, not every situation evoked the same reactions for me, and that doesn't necessarily mean there is anything 'off' about it even if you are used to being anxious all the time. there will be times for whatever reason that what you thought you'd feel, you didn't...when i have those times where i am more at ease than i thought, i try not to focus on the thoughts of 'what was different this time' and focus more on just enjoying myself because once i over analyze something, it can kind of ruin a positive experience for me.

there are also ways people in general are different people at work versus with friends versus being at home alone, so being one way in one place and another in another place is pretty normal too.

best thing you can do if these things are bothering you and impacting how you live your life would be to bring it up to your therapist so they have an idea of what is going on and come help with suggestions.