I think it's normal to draw from past sexual experiences when masturbating without porn. It's natural. You have to find a way to arouse yourself and your memory bank is the best way to do that. It's filled with memories of one night flings, but also if we're being realistic, if you had a longterm partner, you obviously had sex with them on a regular basis and that's going to be a huge chunk of your sexual memory as well. I don't think that's really different from porn. You don't necessarily want to go out and marry the dudes you see in a porn video. Likewise, just because you think about sex with your ex doesn't necessarily mean you want to get back with them.