Seeing Arboretum for the (partial k) Trees -- Collaborating With Hans: Some Remaining Wonderments -- Hans Bodlaender and the Theory of Kernelization Lower Bounds -- Algorithms, Complexity, and Hans -- Lower Bounds for Dominating Set in Ball Graphs and for Weighted Dominating Set in Unit-Ball Graphs -- As Time Goes By: Reflections on Treewidth for Temporal Graphs -- Possible and Impossible Attempts to Solve the Treewidth Problem via ILPs -- Crossing Paths with Hans Bodlaender: A Personal View on Cross-Composition for Sparsification Lower Bounds -- Efficient Graph Minors Theory and Parameterized Algorithms for (Planar) Disjoint Paths -- Four shorts stories on surprising algorithmic uses of treewidth -- Algorithms for NP-Hard Problems via Rank-related Parameters of Matrices -- A Survey on Spanning Tree Congestion -- Surprising Applications of Treewidth Bounds for Planar Graphs -- Computing tree decompositions -- Experimental analysis of treewidth -- A Retrospective on (Meta) Kernelization -- Games, Puzzles and Treewidth -- Fast Algorithms for Join Operations on Tree Decompositions.