Not invited to a party - is the party giver trying to snub you? Is the guest list limited so that you are not being snubbed? Does it mean anything that you are not invited? Extra nice friend - Has your friend noticed that you are not feeling well? Is your friend trying to get a favor from you? Has your friend been really mean lately and is trying make up?
Picking on you - Is this person just a bully to everyone? Does this person think you have harmed him/her? Does this person simply need to be put in his place because he is trying to be more powerful than you?