How frequent are bear sightings along the PCT?

I’m from the UK and I’m planning on doing the pct the year after next.

One of the thoughts in the back of my mind is the fact I’ve never come into contact with bears or some of the other predators native to the US.

I have done plenty of research into bear etiquette, but I’m worried that I will just freeze up if I end up encountering one.

Just wanted to know how worried should I actually be?

Edit: thank you all for your advice and experience sharing. Seems as though mountain lions are more of an issue - what’s the general advice with them? Will do more research but if anyone has tips, it would be much appreciated