I understand what colon syntax does. I know what table.insert(list, value) does. I'm also aware that I cannot create my own table t={} and insert a value to it with t:insert(value). But when I do table:insert(value) it inserts the value to table which is supposed to a type, right? The worst thing is that I can read this value by calling table[1]. What did I just do? How did I insert a value into a type? Why regular tables don't support colon syntax? I tried to Google it up but I just get information about tables in general, not about this particular case.
What did I just do?
The syntax A:B(C) is nearly equivalent to A.B(A, C), you can check my another answer: link.
So table:insert(value) just means table.insert(table, value), it inserts value into the table table (have nothing to do with t).
How did I insert a value into a type?
table.insert(t, value)
Why regular tables don't support colon syntax?
Because t:insert(value) means t.insert(t, value), but this regular table doesn't have the key insert.
You can solve this by adding the function to the table
t.insert = table.insert
Or using a metatable
setmetatable(t, {__index = {insert = table.insert}})