Broadly speaking, mindfulness-type meditation can make you aware of thoughts or emotions that you weren't previously aware of that could be affecting you. Has something ever bothered you, and you didn't realise how much until later on when you got irrationally annoyed at something else and thought "wait a minute, this shouldn't bother me this much"? Mindfulness practices can make you more aware of that emotion sooner so you're not carrying it with you all day. There's nothing inherently odd about it.

There are also other forms of meditation that are intended to increase your sense of love and gratitude (metta), to come to grips with your own mortality (maranassati), and surely other psychological exercises I'm not aware of.