The fact that you can easily improve "funny" skills is almost unimaginable, but undoubtedly right. I should first clear up why some things are amusing, the way scientists claim this to be. Whenever we recognize new things, then our mind makes the new path, from a cell to another brain cell.
This connection is called a synapse and it works like this:
When thinking about cherries , at the same time, we know the apples are food, so, our brain will create a connection (the synapse) between the two neural cells that store all the date we have on food and that fruit. In the future, there are good odds that when you think about food, you'll think of apples, too. You're probably thinking, what does that have to do with me getting funnier? But, it's pretty much all about it, it's actually the way humor works.
The whole process starts with someone telling you an ordinary story. Stand-up comedians call this a setup. Now, you're supposed to think about this story in a certain way. What happens now is that the brain connects the setup to the punch-line you think is the best. A completely different version of the punch-line, that you have not thought of, is what will make you laugh. And in case, you don't get this, the following example will help you out.
The Setup:
What is the most satisfying thing next to being shot at and missed?
The Punch-line:
An income tax refund.
What punch-line did you have in mind? Surely, you would've said it was either a Bosnian, Serbian or Croatian in the driver's seat. Well, just know that it's normal to think that way, as our brain was made to think so. But as I, previously said, you didn't expect this kind of punch-line. Be sure to remember this, as this is the main principle of humor.
The main thing is good setup. Good comedians will always have a setup that only delivers the basic facts, so that there are many possible punch-lines you can think of. The more you are convinced, the more you will laugh after hearing the punch line. In case you have already heard the joke, it will probably not be as funny, simply because your brain knows the punch-line, therefore it won't create any new routes.