You can, your only limitation is your mind. For instance to see the future I will dream of watching a movie I haven't seen that I know is coming out! Or listen to a cd in my dream while lucid and I will hear hit new music! Sometimes I can remember the beat ir hook as i wake up and think wow I could bring this over and be a megastar! lol but then the memories will be fleeting unless you write the dreams down regularly! Also do reality checks, look at tour hands a few times a day and ask yourself if your dreaming. Eventually you will not realize u are dreaming and do the reality check and instantly feel jacked in when you realize you are dreaming! So if you want to see the past dream about watching an old movie! Also you can dream about your computer and go online and do google searches! It’s the bomb! Sometimes the two worlds would collide and i would access my real server and update it from my dream! Once there was data that transferred, i was amazed! It could have been a coincidence, but i kept having dreams about connecting to the wifi!