A warm greeting does not need a complete explanation of your absence.

Guilt turns a hello into a report. Someone who has been out of touch often begins with an account of why, as if the friendship were a debt to be settled before anything else could happen. Most of the time the other person simply wanted to hear from you. The explanation, offered before it was asked for, puts a small debt where there was none.

After a long absence from someone, begin by being glad rather than sorry. Say you have been thinking of them and ask how they are. If the story of the gap matters, it will come out later, and it will come out better.