I disagree. After only 3 dates it would creep me out a bit if my date said "I keep thinking of you" and went out of their way to demonstrate a lot of interest. Some people, like myself, feel much more comfortable moving slowly and doing a lot of friendly talking before demonstrating much romantic interest. If you show too much interest too early, then what is that interest based on? It can't be based on anything other than physical attraction or transference because you don't actually know the other person yet! To me, that's a red flag that the person is probably infatuated with the IDEA of me, or of being in a relationship in general, and doesn't really care about me in particular. I think it means a lot more and has a better chance of working out in the long run if you move slower and get to know the person saying things like that. I would prefer that ove demonstrating superficial interest in order to "hook" the other person.

I know that I don't show interest before I really feel it, and it takes me several dates to develop much interest or real feelings for someone. If the woman I am dating now had stopped seeing me because I wasn't showing a huge amount of interest by date 3, she would have missed out. By date 6, when I WAS feeling that interest, I made her a pretty incredible picnic in the park with her favorite foods and her favorite flowers. I was only able to do that because I took the time to get to know her first, and do something that was really genuine and spoke to the relarionshup we had begun to build. So I do not think the fact that someone isn't showing a ton of interest right away means that they are insecure or wimpy or will never make a move. It very well might mean that they are simply trying to get to know the other person first, so that any feelings they do show will be genuine!