You didn’t actually do the math on that. According to this paper by the Future of Humanity Institute (Nick Bostrom’s group), if life evolved to the point of interstellar travel 3 billion years ago and could travel at 50% of c, then you would expect it to travel not just to this galaxy, but the nearest million. If you go back five billion years and assume travel speeds of 99% of c, it could reach a billion galaxies. 75% of stars in the Milky Way that could support life are older than our Sun. It really is an enigma.
http://www.fhi.ox.ac.uk/intergalactic-spreading.pdf
You didn’t actually do the math on that. According to this paper by the Future of Humanity Institute (Nick Bostrom’s group), if life evolved to the point of interstellar travel 3 billion years ago and could travel at 50% of c, then you would expect it to travel not just to this galaxy, but the nearest million. If you go back five billion years and assume travel speeds of 99% of c, it could reach a billion galaxies. 75% of stars in the Milky Way that could support life are older than our Sun. It really is an enigma.