Farewell Speech for Departing Colleague

I'm giving a farewell speech for [colleague name] who is leaving [company] after [years] years. They worked as [role]. Reasons for leaving: [new opportunity/retirement/relocation]. Their contributions: [achievements]. Impact on the team: [what they meant to us]. Memorable moments: [stories]. What we learned from them: [lessons]. Their future plans: [what's next]. The audience: [team/department/company]. Tone: [funny/heartfelt/professional]. Length: [duration]. Please write a farewell speech that honors their contribution and wishes them well.