Couple examples from personal experience:
Spicy Food
I didn’t like spicy food for a (relatively) long time until I was 25.
2/4 of my roommates did. We’d order two pizzas, one spicy and one not. But the asshats who liked spicy would eat half the non-spicy pizza first knowing the other one was safe from us.
Well… we’d see about that!
I bought a jar of pickled little yellow banana peppers. At first all I could manage was a tiny little bit of one. But I had that tiny little bite every evening, every day. Eventually my tolerance grew until I was eating a whole one, then multiples. In a few weeks I realized I was crunching through them and loving it. (Didn’t love the first time I overindulged and found out what goes in can still burn going out, oof, lol.)
Beer
First time I had beer I did the movie-style stereotypical spit-take. Tasted like something I’d never want again. I drank when I was 18-19yrs old but it was usually Smirnoff Ice or some other “bitch-pop” as was said at the time by those around me.
When I was in my early 20s I supervised for a company that had us do a lot of traveling. Particularly three months of the year I was in a hotel more than at home.
There was a consistent crew of people who lived in a town nearby that I saw fairly frequently for those three months but not too often elsewise. As I said I was in my early 20s, 21-23ish. And they were in their late 20s to mid thirties.
They were inveterate drinkers, and they loved beer. And they undertook a self-imposed mission to teach me to love beer too. Them being older and me being impressionable, I went with it.
Every evening after work we’d hit up the local pub and I’d order three beers, based off their recommendations. One was an inveterate drinker as mentioned, the other a mid-thirties redheaded British woman I grew rather fond of and who was rather fond of me, along with some other crew. Basically, people who knew beer and in the case of the brit, someone who I would’ve listened to for a few reasons.
Didn’t take too long but I certainly “acquired” a taste for it. Eventually acquiring my own preferences to the point I was recommending them ideas.
Bitterness in coffee comes from overextraction, acidity in coffee often comes from underextraction.
On top of that darker roasts tend to be more bitter, and lighter roasts tend to be more acidic.
The main problem is usually the wrong grind size and brew method.
Grinding the coffee too coarsely makes it hard to extract flavours, leading to underextraction (sourness). Grinding too finely makes it easier to extract flavours (both desirable and undesirable) leading to overextraction (bitterness)
Regular coffee makers, pour over, and espresso are all percolation brews. That means that the water flows through the coffee and extracts flavours while it does these kinds of brews can develop channels while the water flows through, which causes the water to overextract the coffee where the channel is, but underextract the rest of the coffee, which can lead to a brew that is at the same time sour (underextracted) and bitter (overextracted)
The other general method of brewing is immersion brewing. This is where the coffee and the water hangs around for a while during the brew, and is then strained away from each other. Good examples are French press, aeropress, siphon, and cold brew. Since these methods can’t really develop channels, you don’t have the same problem with over and underextraction, and therefore these methods are also much easier to “get right”.
So if you want an easy method too get better tasting coffee, try a French press, and be careful grinding too finely. If there’s a layer of silt at the bottom of your cup you are grinding too finely. Pregroud coffee is usually too fine for French press.