The person bragging the loudest is often the least sure they deserve to be there. Real ones just keep working.

Volume tends to stand in for certainty. Somebody secure in what they can do does not need the room to confirm it every ten minutes, while somebody unsure keeps checking. That is useful to know about other people and worth knowing about yourself on the days you cannot stop mentioning things.

Notice when you feel the pull to announce something. Ask what you would be doing right now if nobody could know. Then go do that for an hour before you say anything.