Arranged a meal with some friends to celebrate an occasion, told in advance.
Friend messaged asking if I wanted to do something the night of my event (had obviously forgotten) - I responded that it sounded good but it was actually my event that night and were they still coming. They laughed it off and said yes they would be.
Another of the attendees apologised when I reminded and said they were double booked and could no longer make it.
Luckily most are still coming but aibu to be annoyed and frustrated? Both were done so casually and make me feel a bit insignificant