Just as it were
Not much would be different, I do believe, if I were to go invisible for three weeks. I suppose the same feeling of being unheard and ignored would just be heavily amplified. I'd walk around, I suppose, scanning my surroundings. Watching for ill willed folk and casually carrying along. I'd stop those who meant harm. Give a good scare by grabbing at a mans arm before he goes to strike the lady he is yelling at. I would perform good deeds while invisible. However, I would also tend to myself. I'd leave a note for those I loved. It would explain where I was, sort of anyway. Vacation. Yes, I went on vacation.
Now, my cat would probably freak out if she felt me and heard me but could not see me so I would not do anything to traumatize her.
I assume that I'd be considered missing after a week if nobody saw me at all so as far as that goes, I am sure my fiance and mother will be looking for me even though I left a note. I imagine not much in the world would happen due to my invisibility. Things would change some, though because I would play hero wherever I could. Give the baby their pacifier when their mom is too busy in the checkout lane, help a woman find her keys while she chats on her cell. Her keys, by the way, are dangling in her ignition.
I would be amused by the way things are.
However, I do not mean well completely. I would go to my job and cause just a touch of disorder. Move things around. Maybe drop a bottle of wine. Give them a little show. Nothing major, though.
Finally, being invisible would be way too lonely. I couldn't be seen.
I suppose that's worse than not being heard.
Because if you go physically missing, eventually, people move on. And I don't want to be forgotten anytime soon. I've too much to live for, thank you very much.