Perhaps -- Continuously Thinking About Another Person Has It's Place for Reproductive Purposes

A one-track mind, maybe part of Nature's survival mechanism in relationship to hyper-focusing on someone to reproduce with. Kind of like the "honeymoon stage" when being in-love is part of the bonding for a full-bloomed romance, the one-track-mindness that happens when someone is romantically courting another, may be a very essential part of the desire to romantically bond for reproductive purposes and the survival mechanism for human beings, because (perhaps) the hyper-focus allows one of another person's desire, to be the focus of attraction for reproductive purposes. (And not necessarily the focus, related to an OCD condition.)

Trisha Yearwood sings "Thinkin' About You" -- which is a song, about an individual's continuous thoughts about another person.

Doing Something Right is Even Better When Acknowledged by a Passionate Sigh

Billy Currington's "Must Be Doing Something Right" is a romantic smooth song, about someone who thinks that he must be on on target, or at least in the right direction in regards to pleasing his partner. The passionate sigh of a lover, may speak a lot of words about a partner doing the right thing. Someone who knows what he or she is doing, makes being on the same page and romance a pleasurable natural thing. To be in-sync with one another by being able to read the sighs, is a part of reaching the romantic goal. The acknowledgement and appreciation of someone who knows what he or she is doing, is part of the importance and delight of being a couple.