Is it excusable to forget someone's Name Day?

In some of Europe's countries, including mine, we have Name Days. There are some people that I kind felt close to and I send messages on their birthday or name day.

Am I right to feel PISSED and don't want to talk to those that simply don't care enough to send a message, let alone call ? Should I break it with them completely ?!

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A name day is a tradition in many countries in Europe and Latin America that consists of celebrating the day of the year associated with one's given name.

Is it excusable to forget someone's Name Day?
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