I had some very mind altering drugs during a surgical procedure. Afterwards I realized my perception of reality was completely distorted, but seemed real at the time. It occurred to me that all we do when we travel is move to a place where our sensory organs can sense another environment. We can virtually travel using telecommunications technology. What if an advanced civilization had a technology to virtually transport themselves anywhere in the universe, or alter our perception of reality so that we think we have an awareness of something that isn't physically present, at least according to our current measurement abilities?
UFOs don't make any sense to me. A sufficiently advanced civilization may be able to redefine reality (especially ours) to whatever purpose suits them, including transport. UFOs are so old school.