When you click the topic in either the old location or new all posts will show up. In the forum that the thread was moved from it won't show if there has been any recent replies or who from on the forum page after the thread is moved. It also won't advance to the top of the forum list in the old forum if someone replies but will in the new forum. It's sort of a built in way for a thread in the wrong forum to slowly disappear into the back pages of the forum.
Most times when a moderator moves a thread it's so it gets exposure to more members. Sometimes even though a thread is in the right forum I'll move it to a busier forum if the thread isn't getting any response.
Another tip is to pick your post subject wisely. If the title is something like What if? many folks will just skip it. It will also make a search easier later if you need to find something.
One more tip to find a lost post/thread of yours or anyone else's is to click the search button under each person's post. You will then get a list with a short excerpt from every post that person has made starting from the most recent. Just clicking on the title of one of these will take you to the entire thread.