(lol) You think wrong. kind of sad you won't face your own thinking. So for the record, don't you and others that believe in evolution (the theory of per Darwin and his successors) believe fish were the forebearers of humankind?
Here's an outline of human evolution (which I confess I haven't updated for a decade, but the basics are in order) ─
Human evolution goes from the most basic form of life (protobionts, presently undefined)
to the single cell (Prokaryota) 3.7 bya
to nucleated multicelled (Eukaryota) [though some say Eu- was before or simultaneous with Pro-] 1.7 bya
to bilateral symmetry (Bilateria) ›555 mya
to a stomach with two openings [mouth and anus] (Deuterostomia) ›555 mya
to a notochord [‘spinal chord’] (Chordata) ›555 mya
—
Ordovician - Silurian Extinction 440–450 mya
to a backbone (Vertebrata) ›525 mya
to a movable lower jaw (Gnathostomata) ›385 mya
to four legs (Tetrapoda) ›385 mya
—
Late Devonian Extinction From ~360 to 375 mya
to eggs with water retention suitable for dry land (Amniota) ›340 mya
to eye sockets each with a single opening into the skull (Synapsida) ›324 mya
to mammal-like reptiles (Therapsida) ~274 mya
to ‘dog teeth’ (Cynodontia) ~260 mya
—
Permian-Triassic Extinction 251 mya
to milk glands (Mammalia) ~200 mya
to vivipars and monotremes (Theriiformes) ›160 mya
to modern vivipars (Holotheria)
to proto-placentals and marsupials (Theria)
to placentals and certain extinct non-marsupials (Eutheria) ›160 mya
to placentals (Placentalia) ~110 mya
to all mammals except the Xenarthra [sloth, armadillo, anteater] (Epitheria) ~100 mya
to bats, primates, treeshrews (Archonta) ~100 mya
—
Cretaceous-Tertiary Extinction 65.5 mya
to tarsiers, monkeys, apes (Haplorrhini) ~63 mya
to New and Old World monkeys and apes (Simiiformes) ~40 mya
to Old World monkeys and gibbons (Catarrhini) ~35 mya
to apes [great apes and gibbons] (Hominoidea) ~29 mya
to hominids / great apes [orangutans, gorillas, chimps, Homo] (Hominidae) ~25 mya
to hominins [gorillas, chimps, Homo, H. floresiensis, H. Denisova] (Homininae) ~4.5 mya
to Homo [H. sapiens, H. Neanderthalis, ] (Homo) ~2.4 mya
to Homo sapiens [Homo sapiens Idaltu, Homo sapiens sapiens] (Homo sapiens) 250 kya
to Homo sapiens sapiens.
So you can see that our ancestors separated from the fish line about 385 mya, came ashore maybe 365 mya, became mammals maybe 275 mya, primates maybe 100 mya, then hominids say 25 mya, genus Homo say 2.5 mya, Y-chromosomal Adam maybe 250 kya, mitochondrial Eve maybe 150 kya, and here we are.
Yes, you and fish have a common ancestor ─ because on the present evidence there is at the start one kind of cell which had the excellent quality of being able to reproduce itself. (The study which seeks to find a satisfactory description of that cell ─ the processes of abiogenesis ─ is of course a work in progress.)
But that research, like the list above, works with examinable evidence, and draws conclusions and explains them openly; so if you want to disagree, all you have to do is learn enough and understand enough about evolution and biology to avoid looking like a dope, and then present your own fact-based and openly reasoned conclusions to show that the theory of evolution is in fundamental error.
If it's any encouragement, there's a Nobel Prize in it for the winner.
Funny how no creationist has done anything like that already, eh?