Are there any games that you were really bad at in the past but are now fun to you? Did it just "click" or was it a long process where the game gradually grew on you?

For me, it'd be Gwent, both the standalone and in The Witcher 3 (as well as Thronebreaker). I never touched it in my first playthrough of W3 and I tried getting into the standalone version but I just couldn't figure it out. I was losing every match, I couldn't seem to understand any of the mechanics (even after watching a guide video) and it just wasn't fun to me. However, just the other day, I finally decided to really sit down and grind until I started figuring it out because I wanted to enjoy it both in W3 as a distraction and Thronebreaker so I didn't just have to do the "skip battle" thing every time I lost. Now, I'm highly enjoying even the standalone version and I've directly seen myself getting better at it. Not only this, but it enhanced two other games that were already top-tier for me.

When I was a wee lad, HoMM3 and XCom: UFO Defense were both impossibly cool and impossibly difficult for me. Granted both were demos if I recall correctly, and I didn't spend a lot of time with them, but I distinctly remember how worthless I felt trying to play both. Once I got older and more competent at reading game mechanics however both games opened up for me in a big way.

Nice, I need to sit down and really learn HoMM3, I've had it for a while but never really sank much time into it. I did enjoy HoMM5 though, so I'm sure I'll enjoy it too!

Tetris

In fact, this game has become my usual go-to game whenever I have nothing to do.

Easy to pick up, difficult to master, that's for sure!

Borderlands 2 would be an example of a game i absolutely hated for hours but suddenly started enjoying immensely from one minute to the next.

Nice! I never hated it, I enjoyed it quite a bit but I haven't played it in well over a year. Does it get better in the later game? If I enjoyed the early game and it does that, then I should love the endgame.

Ah gotcha, sounds good!

Tekken series.

Fighting games are my go to genre but even in the arcades, I was not very good at Tekken until 5 and 7. Now I'm really good at 3, 5 and 7 but I've played all of the original line except for the tag series. My mains are Heihachi, Law, Akuma, Geese and Gigas.

I recently found out that a neighbor a few houses down from me was a arcade rat like me and my wife. He has the Tekken 7 arcade machine in his gaming garage. So I guess we fighting a lot!

Hotline Miami.

When I first played it back in autumn of 2018 I got through maybe half the levels and then quit. I thought it was a cool game but too hard to complete it. Then I played it again last year and I got through the story. I enjoyed the style and atmosphere so much that I even completed all the levels with A+ score and unlocked all masks and weapons. It's the closest to a Drive videogame you can get which is no surprise since the creators were inspired by that film. The soundtrack is also incredible. It has since become one of my favorite games actually. Trying to get the highest combo possible is always fun.

I enjoyed the game so much that it made me get the sequel too which is also a fantastic game. A lot of people didn't like the level design much but I actually love how it is more gun focused than the first game which is more melee focused.

Me, it could be Morrowind, I first played when it was a gift in a magazine.
At the time I discovered mods, and filled the game with a lot of mods.
I never found the guy we have to find "Caius Cosadès".
Then bought the game with the extensions at a cheap price. I wasn't very good still.
Purchased the game here on GOG and on steam.
Then, I made progress, finally found "Caius Cosadès", I can handle myself in the wild, etc.
But I haven't finished the game yet, lol.

Diablo III. The loot system was atrocious at launch and reliant on the not-enjoyable real money auction house. It's a much more enjoyable game now, especially with the seasonal reset

Some more awesome answers!

That's an example of a game that I enjoyed but was terrible at until more recently haha

Technically several RTSs make the cut for me in the sense that I enjoyed them from the first moment I picked them up and never stopped being terrible at them. I'm just not fast enough or enough of a multitasker. :)

So my answer can be any of Starcraft, Warcraft 3, KKND, Empire Earth, Dark Colony, Age of Empires...