In reply to Rog Wilko:
There's a sign for Cambeltown just before the Erskine bridge stating a distance of 125 miles. It's easily the furthest distance in the UK mentioned for such a small place on a primary route sign. Road sign distances and destination population ratios only get you so far as very small hamlets or even single houses can be signposted from relatively large distances, but without the destination actually being particularly remote.
(Before anyone comments, yes the signs at Ullapool and John O'Groats state 170 miles in each direction but they are brown tourist signs which would never exist for practical purposes).
As you say it's hard to define remoteness but I would agree that for mainland UK Campbeltown is exceptionally out of the way. Were either Thurso or Wick to stand in isolation they would be contenders but to me Caithness "feels" like an island with a road connection to Inverness.
There are other coastal towns which suffer / benefit such isolation such as Millom in Cumbria, which takes a surprisingly long time to get to and from almost anywhere else. Chronographs of traveling times to London can emphasise just how distorted connectivity is within the UK.
As for growing up in such places it's very hard to return once you've left. I remember a piece of inspired graffiti spray painted on the side of the much underused library in my local home town which stated: "SMALL TOWN. SMALL MINDS". In that particular case it was, still is, painfully accurate. I've not moved back.
Post edited at 02:47