1. Friends or relatives who name their baby the same name or a similar name as your child
You don't own the name.
You didn't invent the name.
The name is not a reflection of you (even if you'd like to think otherwise).
Most important, the kid will never give a damn if someone else shares his or her name.
Imitation is the most sincere form of flattery, so be flattered that someone liked the name that you chose for your child so much that they decided to do the same.
2. Failure to receive a thank you note
We don't send gifts in order to receive thank you notes. Sending a gift with the expectation of receiving something in return is called a trade, and in this case, a gift in exchange for a thank you note is a tragically inequitable trade. We give gifts because we love a person or at least like a person. We should be giving gifts free of obligation or expectation. To do otherwise is petty and sad and cloying.
3. The cost of a gift given to you
If you are spending even half a second contemplating the price of a gift received or (even worse) comparing the cost of a gift given to you by a friend to the cost of the gift you gave to that friend, it is time to start volunteering in an orphanage or a leper colony in order to find some meaning in your life. Gift giving is not a dollar-for-dollar exchange of goods but a heartfelt offering unrelated to expense.