You can't. Use your intuition because some jerks out there look like great guys. I'm like you, and finally, after seven years, I felt something for a guy that asked me out. We had a great time and saw each other 3x. Then, only texts and a few phone calls. It's been a month. Next call, if there is one, I am going to find out what is wrong. He was so gung-ho from the get-go. All the best for a new chapter in your life 💖