oh, well every post, comment or edit is public and written on the blockchain forever... the closest you can get is to edit your post and erase all the content. Anyone can however go to https://steemd.com/@inreallife and see every edit and original post that you made. I also believe there is one weird trick, where for articles that you can find easily on the "new" section, like the one we're in right now, if you click here: https://steemit.com/created/steemithelp, you can go into the "new" section, and there you will have the option to delete the post. I haven't tested this though.