Same here. I lost countless occasions to express an idea or a joke because I didn't manage to speak and the topic shifted enough that the idea became off-topic when I could speak.
But I usually don't think I'm more relevant than the person who managed to speak before me or don't have the energy to impose, so I just listen.
In a group of 3 or more (especially more) people, there is probably no way to avoid this happening to at least some of the participants multiple times. There simply isn't enough time to get every word in before things get tiresome and people need to re-arrange.
It took until I was well into adulthood to come to that realization.
I've come to enjoy the feeling of having had a good idea to contribute, but seeing that the situation doesn't call for my input, and just letting the moment pass. It's fun to have ideas, and it's fun to figure out whether or not it is the right moment to make your contribution.
But I usually don't think I'm more relevant than the person who managed to speak before me or don't have the energy to impose, so I just listen.