A train that has to move along a certain net of rail lines has a certain freedom of movement. It can move backwards or forwards, it can branch off in different directions. Unless of course we add some additional rules and assign the train to one particular route and one particular schedule to follow. At any rate it does not have full freedom of movement. It can move in certain ways according to certain pre-determined rules, and that is all that it can do. It can not take off across the countryside as it pleases. And even though it has a certain range of movement on the tracks it has to do what makes sense for a train to do.
Meaningfulness and logic are in the realm of maps, not of territories. To talk about logic you need to outline a model of some kind and then manipulate the elements of the model or compare things to it. If I say that apples are green in the spring and red in the fall, then a green apple in the spring is logical and a red apple in the spring is illogical. And a pink banana would be meaningless because I didn't say anything about that in my model.
But in itself, viewed separately from any models and ideas, an apple is neither logical or illogical. It just IS. Its meaning is that it is there. What is there is what is there. Any additional meaning added to the situation would be a mental construction, not a true reality.
The universe is a dynamic, flowing activity. One deals best with it in a dynamic, flowing way. Whenever one tries to force the universe into a more fixed, limited model one is heading for trouble. As long as one remembers that a model is a model then it can be quite a useful tool. But the moment when you think that the world really is like that, then you might not see the freight train when it comes, because it wasn't on your schedule.
If you can stay continuously in sync with the situation you are in, and you have a wide range of possible action, then you can always do the most appropriate thing at any given time, and get the best possible result at any time.
The number of meaningful, logical, explainable actions one can do is finite and limited. They are only a small sub-set out of the totality of all actions. If you get yourself used to only use those actions you confine yourself to only a small dangerous neighborhood of reality.
If you are lying on the tracks when an express train is coming straight for you at 200mph, then the logical thing to do would be to get run over and die. That would make sense. You are here, the train is there, we calculate the crossing of your paths mathematically, and BUM! The illogical, meaningless thing to do would be to just suddenly not be there when the train hits, but to be 10 miles away having a cup of coffee.
Most great inventors and pioneers in most areas did what they did by breaking the rules, by doing things that didn't ordinarily make sense. They make sense afterwards, but at the time they were considered impossible. Columbus sailed out where everybody said he would fall off the edge of the Earth. Graham Bell invented the telephone despite his contemporaries regarding it as silly and useless.
Doing meaningless things can be quite a useful ability. You can always add meaning afterwards, and then your actions become very meaningful, of course. But any act of genius is made by venturing into the realm of the meaningless.
Meaningless actions aren't just actions that are wrong according the prevalent maps. They are actions that go beyond the maps and deal with the real world rather than with mental constructions.
You can learn to do meaningless actions gradually. You can explore the full range of motion of your body, your voice, your language, etc., without any regard as to an expected outcome. You can get used to the idea of doing actions that are divorced from any idea of reward or logical cause-effect. You can challenge any boundaries you feel you have as to what one can or can't do.
There are strong social, moral, and personal forces trying to stop something like that from happening. Part of increasing one's capacity for meaningless action is to deal with all the reasons why not. All kinds of old patterns are likely to be activated that will block free expression. These can all be dealt with with semantic processing.
So, why should you bother at all to learn how to do meaningless actions?
For no particular reason at all.