I think that part of the OP's observation that "everyone" in his/her classes are engaged or otherwise is because this observation is being taken at a community college.
Think about it...most people who go to community college are older students...most are people who have a spouse or kids (or are a single parent). Certainly not all comm. college students fall into this category (a surprising number of them are high school students), but I think it is enough to skew the "results".
A community college isn't a representative example of traditional college age students.
And OF COURSE 20 year old females are thinking about marriage...they are figuring out what rings they like, dresses they want, etc. etc.
PsychTau