Final answer:
Alex could have been 11 the day before yesterday and be turning 14 next year if his birthday is on December 31st, making the scenario possible by taking into account the current date as January 1st.
Step-by-step explanation:
The question presents a brain teaser that at first glance seems impossible but can be explained with a simple twist on perspective. The key to understanding how Alex was 11 the day before yesterday and will turn 14 next year lies in considering the current date. If today is January 1st and Alex’s birthday is on December 31st, then the following scenario is possible: The day before yesterday, which would be December 30th, Alex was indeed 11. Yesterday, on December 31st, Alex turned 12. As today is January 1st, Alex will be 13 for the entirety of this year, making the statement true that next year, Alex will turn 14.