Lately after a long process of self improvement which caused a lot of confidence in me I often get told I look older than I am due to "the way I carry myself"

I am twenty two and can be mistaken for up to 30 years old. The reason that is according to them is because I "carry myself like an older man".

Specifically in elaboration my rate of speech, walking and sitting posture have been mentioned referring to the aspects that show confidence.

I suppose the way to take this is as a good sign however it feels strange and it could prove counterproductive. What are your thoughts?