You use can to indicate that someone has the ability or opportunity to do something.. Don't worry yourself about me, i can take care of myself.
/Paintingbrickwall-GettyImages-1175471455-9c0c87f8d2064fb986050e2bed65f8bf.jpg "How to Paint Brick")
Spaghetti hoops come in a can.. The use of can to ask or grant permission has been common since the 19th century and is well established, although some feel may is more appropriate in formal contexts.