We changed most of the bulbs in our creaky old house (i.e. 37 year-old house; this is the US) for compact fluorescents a few months ago.
The so-called 'instant on' compact fluorescents take about a second and a half to switch on. They're 'instant on' because they don't slowly lighten up from stygian gloom to actinic glare over the course of fifteen minutes like the older type. But the 'instant' part is not strictly true.
Now it doesn't, cosmically speaking, matter if it takes a bulb over a second from lightswitch to illumination. But after several months it still brings me up short. Physically, I'm fine with it. I've learned to hit the switch, stand still for a second, and then walk into the room as the light comes up. Psychically, it's still disconcerting.
The word for knowledge or grokking is 'illumination'. For some time, way back before I was born, the usual symbol for that moment of instant understanding is the light bulb flicking on. The pronunciation is related to light-switches too. We say something has 'clicked'. To go through the house and 'click' and not have the lightbulb obey instantly still jars something inside.
There are murmurings - now reaching a low roar - that incandescents will soon be banned. My iguanas won't like that - they use almost a kilowatt of light as heating during the day. The fluorescents, even 'instant on' ones, won't supply heat. (We have solar power, so don't bother writing in about what a wasteful git I am. And on really sunny days we cut out the middle man and put the iguanas directly under the sun and switch their heat lamps off.) The house wiring won't like that either. The mains is pretty lumpy inside here and it's eating the fluorescents for breakfast.
Disposing of the dead bulbs is always fun. As they are considered hazardous waste because of their mercury content, we have to drive them to the dump where men in chemical hazard suits carefully lift them from the back of our car with gloved hands and then unbundle them from their poisonous content by some secret method to which we are not privy.
I'm hoping something with LEDs will happen soon and I won't have to worry about the mercury thing.