We all know, but we are all also in the dark (or see through a mirror dimly, as Paul suggests).
Based on God's side of eternity (damnation and the Lake of Fire is somewhat different -- mostly on the blessing/joy end of things):
We will be fully ALIVE! We will SEE God and live! Finally! There will be joy unspeakable and impossible to understand in our current cursed form. There will be love -- agape love!
We have bodies (eventually, we begin our journey as non-corporeal until the last day) -- fully functioning human bodies, designed according to God's divine design parameters and intended to last eternally. Whether or not we have "enhanced" functions, etc., is anyone's guess. Some have made that guess based on what Jesus did post resurrection, but that may not be our same case. We'll all know one day.
We will not suffer pain. We will experience emotions. We will be able to talk, move, sing, raise our hands, walk, etc. We will be able to eat and drink. We will have memories from the prior life. We will see people, recognizable (and seemingly, we will recognize them even if we never met them in person), and we will see people of every race, gender, language, and ethnicity from both before Christ and after Christ. We will (finally!) be ONE as God is one. There will be children.
We will have work to do -- godly, rewarding work. There will be human leaders, who (based on inference) will direct our work and our actions. There will be commerce. There will be roads and travel. We will have some form of abode (house, room, etc.) in which to live. There will be trees and animals. There will be precious stones and gold.
We will see and interact with the angelic realm, and the special creatures that God has created to worship and serve His throne.
All of the above can be demonstrated with direct Scripture quotations gathered from various places in the Word.
Based on the above, I have drawn some interesting (but un-supported) potentials:
The cosmos... We are reminded in Scripture that the cosmos declare the glory of God. It is entirely possible that in God's command to be fruitful, multiply, and fill the earth, that God intends for us to fill the entire universe. We cannot know that, but it is fun to speculate. Imagine, with the power to live forever, and the full ability of God to allow us (or give us) the full scope of possible technology, being gone on an expedition that lasts for a million years, then returning to celebrate at the throne of God, recount adventures, and love people, then do it again in another direction. Such is only the beginning of possibilities with eternal life.
Relationships... On the single best moment of human married life, when the love for spouse overwhelms us to tears and we just bask in each other's arms, filled to overflowing with emotions, we experience but a foretaste of the true loving relationships we will experience in eternity. Where every person is totally surrendered to agape love, and who has nothing but the best interest -- without reservation or guile -- for everyone else, the entirety of eternity will be the most amazing love-fest possible. We will finally experience God's love completely, and we will finally get past our own sin nature that hinders our love toward each other and FULLY love everyone. Oh, what a joy inexpressible!
Worship... We make much of worship, but we always worship here on earth in circumstances that are less than ideal. Worship with God in sight, the glory and majesty that is His throne room, the expanse of the heavens and the light that is Jesus Christ illuminating us, the almost un-countable number of people and angelic beings joining in that heavenly chorus, the God-gifted musicians who now play, fully enabled, their glorious melodies directly to God and for the benefit of all... We WILL EXPERIENCE worship that utterly devastates us -- and utterly makes us alive at the same time. The weak and partial vision of God on His throne, receiving our worship, then -- finally -- standing to acknowledge the truth and spirit of that worship while His created beings explode in godly joy... I. Want. To. Be. There. To. See. Taste. Hear. Touch. And. Experience. That. Worship. Maranatha~!