I am suffering from depression and CPTSD which affects my thoughts and emotions. I find reading, critically evaluating ideas, etc. very difficult due to my illnesses. You could argue that I do not have a sound mind. When I asked "Is solipsism true?" what I meant is that "Is solipsism real? i.e. am I the only real entity in all of reality?"
Yes, I know how to ride a bike, how to walk, how to read and write, what my address is, the names of my parents, and millions of other things. I don't have the time to list millions of things.
I think we are using very different definitions for free will. Although you have not stated which definition of free will you are using. I am inferring that your definition is "Free will is the ability to decide what to do independently of any outside influence." My definition of free will is a will that is free from determinants and constraints. I am talking about both internal (e.g. genes) and external (e.g. environments) determinants and constraints.
If I had the genes of a banana tree, would I be able to type this post? No. I have seen many banana trees and none of them can read or type or even know English. They are probably not even sentient.
If the zygote that was I when I was conceived was placed inside an oven at 250 degrees Celsius for an hour would I have become the adult I am now? No. The lethal environment would have destroyed the zygote.
If the zygote that was I when I was conceived was deprived of all nutrients would I have become the adult I am now? No. The lack of nutrients would have killed the zygote.
If the zygote that was I had all the correct genes and was in the correct environment and received the correct nutrients then I would have been born as a healthy human baby. If that baby had different experiences from me such as learning Japanese instead of English, I would not be typing this message.
So, do you now see the roles played by my genes, environments, nutrients, and experiences in the typing of this post? This is why I am convinced that we don't have free will. Do you understand my thoughts and reasoning?
I gave you a list of tasks to complete to prove that your will is free from determinants and constraints, but you failed to do the tasks. You claimed that the mind is free but it is not actually free. Can you become fluent in 6000 languages you don't know in one nanosecond? No, you can't because your mind is not free. Your thoughts are most likely the product of the electrochemical activities of your brain and they are subject to the laws of physics. The state of your brain not only depends on the laws of physics but also depends on your genes, your environments from conception to the present, all the nutrients you have consumed from conception to the present, and all the experiences you have had from when you were in the womb until the present. Therefore, your mind is not free from determinants and constraints. If you can prove to me that your mind is free from determinants and constraints, please do.