Going Pyramid

My friends from primary invited me to pyramid next Monday and I initially didn't wanted to go because they were going to lagoon too.I'm having a "fobia" to lagoon cuz I had a bad experience there and don't know why I just don't enjoy playing those rollar coaster and stuff cuz I'm terrified of these things.Do not say that I'm useless for not enjoying these kay?So I was planning to tell them that I will join them later on after they are done with the lagoon thing.So good luck to me.