Reflection is an essential element of all learning activity for an individual.
If you don’t have a focus though, it’s easy to just review something and, like a mirror, let the thoughts bounce away.
A concave mirror is curved inwards so that light striking it is centered onto a focal point.
A convex mirror is curved outwards so that the light striking it diverges and spreads.
Reflection for you needs to be concave. Reflection for others needs to be convex.
Don’t mix them up.