I sometimes wonder about that. The sheer level of increase in knowledge and technology in the last 120 years has been prodigious ...so dazzingly fast that what we take for granted now (e.g. cellular communication, commercial flight, modern medicine, weaponry) would have been in the realm of telepathy, magical flying devices, alchemy, and infernal-sorcery to those born in prior centuries. Thus, we have progressed far.
However, I recall the Roman empire and what followed once it collapsed. The knowledge that was lost after the collapse of Rome, and the coming of the Dark Ages, was lost for over a thousand years. It had to be 're-discovered' many hundreds of years later - slowly. The world went from a time of technological progress (e.g. medical progress, piped and heated water, good standard of amenities) to a true retraction of knowledge and roll-back in a lot of areas.
Looking at current levels of technology, to the extent that it is so far-advanced, and so specialized (e.g. the engine used in the Eurofighter Typhoon is too advanced for a nation like China to make ...actually they only recently managed to make a reasonable copy of the Russian RD-93 engine, and even then the Chinese version is underpowered and not as good), that if something (some event) was to occur that hit modern civilization, so much knowledge (and especially know-how and the means of production) would be lost that they may have to be rediscovered.
For instance, let's say some global pandemic was to hit (e.g. the perenial fears of some super bug) and lay waste to a significant portion of the population ...that would lead to a new Dark Age (not as dark as the one before, but considering how far we have come, even going back to where the world was in 1945 would be a HUGE step backwards).
It is definitely VERY possible that a 100 years from now, Earth will be an amazingly advanced place with all sorts of marvels that we would now shelve under 'science fiction' (the 'magic' of today). Where disease is a (mostly) forgotten thing (at least if you have funds), where even death is questionable (there was a time flying to the moon was impossible, and when infant mortality a given), where the standard of living is so good that being 'poor' means a person lives for a hundred years rather than five, and where lack and want are mostly relegated to needs. On the other hand, it is very possible that a hundred years from now Mankind will not be 15 billion people (btw it is interesting the globe took a hundred years to go from 1 billion to 2 billion people, and then went from under 2 billion people in the 1910s to almost 7 billion now in a hundred years) ...instead the population of the world will be much less due to global pandemics, resource wars (not just for what we call resources now, but rather for water and arable land), and all sorts of other not-so-nice stuff. We could be a metropolitan Utopia that is analogous to Krypton, or we could be Krypton after the red sun exploded (apologies to all who do not like Superman).
Anyways, in a nutshell, it is very possible that 100 years from now people will be living like how guys lived in 1910.
I'll allow for the possibility that our civilization could wind up there in a hundred years, and that the advance of technology on this planet could actually go backwards, but in the scenario I laid out, technology will continue to advance, and even the rate of advance will quicken over time.
We can throw all sorts of Armageddon-like what-ifs into the mix, but the point is, if a culture can survive its own destructive nature, it can advance to levels where it achieves an awesome degree of mastery over the physical universe.
I'll even allow for the fact that not every culture will be oriented to technological innovation. We see this difference between cultures on our own planet.
But, if we can widen the examples set by the various cultures on this planet to extend across galaxies, then we see that at least some of the cultures that may exist out there will take the path that our own has. Ours is one of constant improvement, discovery, and innovation in the physical realm, and there's no indication that this proclivity is likely to change.
An extraterrestrial culture with the same bent toward technical innovation, and with a head start on us, would possess technologies that boggle our minds, and which would seem to us to be straight out of science fiction.