Reversible/Irreversible Compression/Dilatation

Luscinia

Help me connect the dots here, please!

It's written in my notes that Reversible Compression have less work involved in comparison to irreversible compression while Reversible Dilatation have more work involved than irreversible dilatation. Why? My notes have the graphs and mathematical (integrals) as explanation, but I'm really having trouble picturing it in my daily life.

I'm also having trouble picturing an irreversible work in a piston/cylinder system. Why is it possible to reverse the work done after adding small weights on a piston by removing said weight one by one while throwing a big brick onto it would result in an irreversible work?