I put some fresh electricity in it!
Maybe it is on its way out.
There you go then.
If you left it long enough to NEED a re-charge then the capacity of the battery to hold charge is reduced.
When walking down the street and hearing hoof beats expect to see horses not zebras.
If your battery was needing attention last weekend then that's the first place to look IMHO.
The clicking is the solenoid which is the main switch between the battery and the starter (not enough juice to open the circuit fully) - with the ignition on, short across the two terminals with a screwdriver CAREFULLY! Sparks!!!!
If you get the same click your battery is focced. If it spins the starter then it's the starter circuit between the bars and solenoid.
Whale
PS Just a thought but if you took the battery terminals off to charge the battery, are you sure they are on tight now.....? May have vibrated loose - same issue, not enough juice flowing to trigger the soleniod.