It is all about self-protection. And yes, it is hard to set boundaries and say 'no'.

It is also important to be consistent and firm in these boundaries as giving another person mixed messages is confusing for all parties concerned.

There needs to be accountability as well - if I say 'no', then say 'yes' I can't put all the 'blame' onto the other person for breaking my boundaries. Why? Because I am giving them mixed messages and this is on me, not them.