What does it mean to be peakier and valleyer?

Answer 1

It means when one is really gifted at certain things and possesses great strengths and talents in some areas, but also has things he or she needs to work a little harder to be successful on, which are their weaknesses. Basically it means they can do some things really well, but they just need a little bit of help doing other things, which does not mean that they "can't" do it. They can, as long as they keep trying and don't give up and they get the support they need to be successful.