If something touches you when you are alone, how do you come to the conclusion that it was God? even if you felt warmness.
This is quite the opposite with Jesus when crowds were pressing against each other and He asked who touched Him when the lady with bleeding problems touched the hem of his cloth. His disciples thought he was crazy.
I would add there is one experience I had that really stands out to me. I don't know how to explain it by simply natural means. It was when I was asking prayer to be filled with the Holy Spirit. The exact wording I don't remember. I just wanted to have the Holy Spirit and know I was a child of God. What I experienced during prayer to be filled with the Spirit seemed so powerful it was hard not to believe it was God. I did question the experience though because I tend to question many things.