That means that they ought to know me reasonably well and I would have expected that my range of skills (or lack thereof) would influence their views about me.
So I'm constantly surprised at the things that they endorse me for!
I could understand that I've convinced people that I know something about science and experimental physics (even though I feel far from expert). I feel flattered to have had some endorsements for Public Speaking too, but I'm progressively baffled that others consider that I know anything useful about the rest. I know a little basic Optics, my Computational Physics experience is limited to being reasonably capable of using Excel. Spectroscopy and Simulations are way outside my comfort zone. I once wrote a programme in Fortran (but I was still at school at the time), and when it comes to LaTex and IDL I can only say that I know what they are for.
But I have been generously endorsed for all of them.
I appreciate the compliments, but it must be said that they don't add value to my profile. And where are my endorsements for Engineering, Vacuum or Cryogenics, for Atheism, Skepticism (not Cynicism) or Islamophobia, or indeed for Lateral Thinking or Sense of Humour? I hardly recognise my own 'reflection' that comes from the opinions of my friends and colleagues.
I can't imagine that I'm unique in this respect. I'd just caution everyone to take no notice of the supposed endorsements in LinkedIn.