I don’t think it matters how old you are, one of the hardest parts of mindfulness is unlearning an entire lifetime of somethings things you didn’t even know you were learning.
Avoidance is one of those things. It is not the avoidance that we think about, as in hiding. It is about avoiding doing the learned behaviours and allowing the learned thoughts to make up our minds for us.
Can you actually watch your own thoughts and feelings, without thinking them or feeling them. No of course not, but watching, is different from connecting those thoughts and feelings to anything. Not just negative things, but anything.
This is mindfulness. Thoughts and feelings come and pass, observe them for what they are, avoid the connections to anything.