The point is that the argument that joining the Eurozone
will somehow erode national values, dilute one's unique cultural identity; etc. is greatly overstated, given the actual experience of other states that have joined.
Anyway, take your time and join when you're ready. No rush, really.
I'd be curious to see polling on how immigrants to Britain in the past 20 years feel about joining the Eurozone. I'd bet they're much more pragmatic about the issue.