When talking about Lacan's mirror stage, it is usually about a baby at the age of 6 months recognising itself as a subject in the mirror for the first time. But if you now look at the whole period of a person's life, there are always moments when the person finds himself in such a situation.
For example, during puberty: one day the young person wakes up and notices changes in their own body. The breasts have grown or the first pimples sprout on the previously pure children's skin. You put yourself in front of the mirror and you don't recognise yourself at first... This is a very natural part of life: people develop and the body changes.
In general, the mirror stage is equivalent to a moment of identification. You look in the mirror and realise that the person you see in the mirror is yourself.
The ageing of the human body also contributes significantly to these moments of identification. Not only in puberty, but also later in old age one looks at oneself in the mirror and asks oneself whether one is really looking at oneself. Have I always had these wrinkles? Have I always looked so old?
In my opinion, there are always moments in life when you recognize yourself anew when you look at yourself in the mirror.