Umar bin Abdul-Aziz d.101 (may Allah have Mercy on him) said:
اذا رأيتم الرجل يطيل الصمت
ويهرب من الناس فاقتربوا منه فإنه يلقي الحكمة
If you see a man constantly being silent and avoids socialising with the people then get close to him. Surely, this man has been given wisdom.
Ibn al-Jawzai in At-Tabsirah 2/289