This passage was first spoken to the disciples (you, see also 13:5), but it is also directed to everyone who hears or reads the Gospel of Mark (everyone).
Keep watch!: Although 13:32–37 warns believers to be ready, the early church understood this watchfulness as joyful expectation for “the blessed hope and glorious appearance of our great God and Savior Jesus Christ” (Titus 2:13). Even Greek-speaking Christians in the first century used the Aramaic prayer Marana tha (“Come, Lord,” see 1 Corinthians 16:22; Revelation 22:20). Christians today still “crave His appearing” (2 Timothy 4:8).