Humans learn everything they know through experience. We know what hot feels like from touching a stove or what hunger is by missing a meal. However, someone who has never experienced missing a meal will not understand hunger. They may have been told about it by someone, but it is only when they have actually experienced hunger that they truly understand it. In turn, the concept of infinity cannot be truly understood by humans as humans have no experience of infinity. It is possible to define infinity. There are varying definitions, such as being something limitless or as not being finite. Nevertheless, humans do not experience anything infinite. Everything that humans experience throughout their lives has a beginning and an end. For instance, a runner starts running and will have to finish sometime depending on his or her conditioning. Human lives have a beginning and an end. Those who are living now were at sometime not alive and now are. At some time their lives will come to an end. We know this through the experiences learned throughout life. .
Human knowledge cannot understand infinity. It is possible to conceive the idea through examples, such as self-nesting and counting to infinity in an infinite amount of time, but none of these may be experienced by humans. If you wanted to teach a child who had no experience of the number two, you could give him or her two toys. They would then have the experience of two as being one and one together. The experience of numbers becomes more complex as the numbers increase.
Humans have a difficult time with the concept of numbers greater than twenty. We can visualize in our heads three people, but picturing 1,000 people is difficult. In trying, we will picture a lot of people, but how do we know that there are 1,000 and not 900. The reason is humans have no experience with a number that large. Trying to visualize infinity in our heads is impossible.