Why do I like to bowl?
Well, first of all it's a game of skill, and there are several levels that you can achieve.
For example, beginners who aren't very good (some beginners are "naturals") can aim to score at least 100 points every game. If they are in a league that would give them a "300 series." They can then shoot for a "400 series," which can be achieved if they can score an average of 135 points in each game.
If they can convert a couple more spares in every game (for example, figuring out how to consistently get the 7 pin - for left handers, or the 10 pin - for right handers) they can then start thinking about a "500" series. Of course the ne plus ultra is to consistently have a "600 series" - that's averaging 200 points a game. That takes the ability to string together some strikes!
And it's a thinking game.
You have to figure out what the oil pattern on the lanes is doing to your ball and to adjust to it. Of course this only works if you are a consistent bowler and hit your mark every time - or at least most of the time. Then you can figure out, "Well, the hook at the end is too early or too late, so I need to stand here or throw it out there..."
It's a mental game - once you can get consistent with your form and not "tug" the ball or choke during times when you really, really need to get a spare!