Some are anonymous.  When they zap your profile area, instead of a note.

Sometimes in your wallet they leave a message.  But some just send anonymously. 

 Also, tomorrow and Friday both days are #zapathon
From 4:00pm to 4:30pm central standard time (usa) you will have to figure that time out where you are.  Nostr lights up like crazy with people zapping each others memes and notes.

I would get familiar with adjusting your zap size amount.  Set it low for now like 20 sats or whatever.  It may be on a high default like 500 sats.  Be careful with this. 

 Glad you mentioned this, as a new user my default zap amount was 1,000 after just installing 

 What is a zapathon? 

 At 4:00pm central standard time (adjust to your time zone) to 4:30pm, on Thursdays and Fridays, we send memes and notes, with the zapathon (hashtag) and zap each other as fast as we can!  The screens go by so fast, its basically a lightning speed round!  Its fun!  Bring your best memes!