Other mistake: When Jim Carrey runs out of gas, and takes his what appears to be either a one or two gallon gas can and fills it, the quantity dispensed shows 5.74 gallons.
Other mistake: When Carl is in hospital after the accident with Terence's car, the time is mentioned as 5.40 am but the amount of light coming through the blinds would suggest that it is much later in the day.
Other mistake: When Carl is playing dance dance revolution in the bar, you can see that there are 0/2 credits in the game while he's playing.
Other mistake: When Jim Carey drives up to the Griffith Observatory, the sun is in the southeast for most of the scene (they are north of the building), but in a few of the shots you can see that the shadows are going northeast, meaning the sun is in the southwest, meaning it is late in the afternoon rather than early in the morning.
Answer: They had donated all their clothes to the clothing drive for the homeless. After all, they couldn't say no.
Brian Katcher