Mormons believe in “exaltation”, which is essentially becoming a God, living like God. Now, orthodox Christianity (especially Catholicism and Orthodoxy) has always had a belief in deification or theosis, however the foundational beliefs of Mormonism vs. Catholicism/Orthodoxy make the implications of those beliefs very different.
LDS believe that to be exalted, one has to, among other things, receive various ordinances performed by the LDS priesthood (whether in this life or the next), including baptism, confirmation, Melchizedek priesthood ordination (for men), the Endowment, and eternal marriage (or “sealing”). They believe that to be exalted, you have to be eternally married to your spouse (and the related belief is that God the Father is married to a Heavenly Mother (some LDS prophets have taught that Heavenly Father has multiple wives).
Following from the beliefs in eternal marriage, exaltation, and the Father being married to a Mother, there is the belief that in the next life, those that are exalted, while still accepting God as their God, will have the opportunity to have their own worlds, and have “eternal increase”, or the ability to create spirit children, just like our “Heavenly Parents” did. It has been taught that these spirit children will have the same relationship to us as we have to our Heavenly Parents. Implicit (and sometimes explicit, depending on which LDS prophet one is reading) is the belief in multiple gods, and some believe that God the Father had a Father, an eternal regression of gods.
Heaven is not an isolated experience in Catholicism. Heaven is viewed as a family experience. We may very well be with our earthly, nuclear and extended families, however we will also be with all those that receive eternal life, and they will be our family too. For Catholics, deification and Heaven involves becoming like God, and this involves living and loving like God does. God loves all of us, and we are all one Family to Him, and therefore that is how we will experience Heaven. There is no concept that we will be isolated from others, or that we will forget our families. We will be with them, through God’s mercy and grace.