Is it normal for your tastes to change over time?

Yes, people change as they age.

I used to love salmon. Now I can barely take a few bites before I get nauseous.

Absolutely.

If you ever had COVID, that changed a lot of people's taste and smell. If you have long term it's almost a permanent change. I know at least two people that can't stand either taste or smell of things they used to love.

It's not just the taste buds that change, it's a sensory issue. Fix yourself something simple but also find something rotten. Everytime you try to take a bit of the food item bring the rotten item up to your nose. You will actually train your sensory system to not like the food item. It can also work in reverse but may take a little longer.

It seems this is normal.

I love hard-boiled eggs but sometimes I'll eat one and feel nauseous and it doesn't taste good. Variable quality, maybe.

It's not normal to be sickened by the thought of eating toast, eggs and fish especially if you had no problem with them before. There's something wrong with you neurologically.

I think it would be a cause for concern if your taste DIDN'T change over time. It's perfectly normal and healthy, and pert of growing up.

I hated cilantro as a kid, now I can't get enough of it!

Yes, I believe I read somewhere long ago that your tastebuds change every 7 or so years. I can't remember if that's the exact number or not, but I absolutely believe they change over time.

There are many foods I loved years ago that I really don't care for now, and those I was not a fan of that I really enjoy now. I also think that as you try new foods, that can alter your food preferences as well. I used to think a lot of convenience foods and so-so quality foods were delicious, and after getting into cooking and trying recipes that blew everything I liked before out of the water, I've become more selective when it comes to food quality and flavor, and find that all of the boxed dinners I used to love are so "blah" now. While I used to use pre-made spaghetti sauce all the time and loved it, ever since making my own, every time I've just decided to make a quick meal and use the pre-made, I'm disappointed.

Pretty sure interests and tastes are supposed to remain static throughout your entire life. What you liked as an infant should be what you like as an adult

Of course. People evolve and your metabolism changes which influences what foods are appetizing and which aren't.

Do you mean just the taste sickens you or they upset your stomach?

I used to not like The Rolling Stones. But now I do.