I'm in London (Zone 4 so not central) and yesterday I went out to shops and on the way back passed pubs and restaurants with people in them and I've just spoken to a friend who said she's been invited for drinks in a local pub for someone's birthday (she's not going). Other people have told me their gyms are still busy, quieter but still people there.
I honestly think until there is a lock down people (not all) will continue like it doesn't apply to them and the disease will continue to spread.
Also, I know people who intend to get away at Easter which only will spread CV further. I'm normally the least hysterical person but I can't a see how the spread can be curtailed if a lock down not implemented