  The present work aims to examine in detail the depletion of lithium in solar
twins to better constrain stellar evolution models and investigate its possible
connection with exoplanets. We employ spectral synthesis in the region of the
asymmetric 6707.75 \AA Li I line for a sample of 77 stars plus the Sun. As in
previous works based on a smaller sample of solar twins, we find a strong
correlation between Li depletion and stellar age. In addition, for the first
time we show that the Sun has the lowest Li abundance in comparison with solar
twins at similar age (4.6 $\pm$ 0.5 Gyr). We compare the lithium content with
the condensation temperature slope for a sub-sample of the best solar twins and
determine that the most lithium depleted stars also have fewer refractory
elements. We speculate whether the low lithium content in the Sun might be
related to the particular configuration of our Solar system.
