Wireless networking can be troublesome… usually I never have problems, but every now and then I’ll go to a coffeeshop or a café where I can’t just open up my laptop and immediately start surfing.
The problem solver in me wants to figure out why, what setting needs enabling, etc.
The person who wants to cut the crap restarts the machine.
Restarting almost always is the best course of option. If it still doesn’t work then diagnose it.